diff --git a/accessible/base/ARIAMap.cpp b/accessible/base/ARIAMap.cpp
index 960716e360..3a21725cb2 100644
--- a/accessible/base/ARIAMap.cpp
+++ b/accessible/base/ARIAMap.cpp
@@ -44,7 +44,7 @@ static const nsRoleMapEntry sWAIRoleMaps[] =
     eNoValue,
     eNoAction,
     eNoLiveAttr,
-    kGenericAccType,
+    eAlert,
     kNoReqStates
   },
   { // alertdialog
diff --git a/accessible/base/AccTypes.h b/accessible/base/AccTypes.h
index aa0582adb5..4833e3f785 100644
--- a/accessible/base/AccTypes.h
+++ b/accessible/base/AccTypes.h
@@ -68,20 +68,21 @@ enum AccType {
  * type, the same accessible class can have several types.
  */
 enum AccGenericType {
-  eAutoComplete = 1 << 0,
-  eAutoCompletePopup = 1 << 1,
-  eButton = 1 << 2,
-  eCombobox = 1 << 3,
-  eDocument = 1 << 4,
-  eHyperText = 1 << 5,
-  eLandmark = 1 << 6,
-  eList = 1 << 7,
-  eListControl = 1 << 8,
-  eMenuButton = 1 << 9,
-  eSelect = 1 << 10,
-  eTable = 1 << 11,
-  eTableCell = 1 << 12,
-  eTableRow = 1 << 13,
+  eAlert = 1 << 0,
+  eAutoComplete = 1 << 1,
+  eAutoCompletePopup = 1 << 2,
+  eButton = 1 << 3,
+  eCombobox = 1 << 4,
+  eDocument = 1 << 5,
+  eHyperText = 1 << 6,
+  eLandmark = 1 << 7,
+  eList = 1 << 8,
+  eListControl = 1 << 9,
+  eMenuButton = 1 << 10,
+  eSelect = 1 << 11,
+  eTable = 1 << 12,
+  eTableCell = 1 << 13,
+  eTableRow = 1 << 14,
 
   eLastAccGenericType = eTableRow
 };
diff --git a/accessible/base/Logging.cpp b/accessible/base/Logging.cpp
index b8f112bef3..46dc4c9f86 100644
--- a/accessible/base/Logging.cpp
+++ b/accessible/base/Logging.cpp
@@ -45,14 +45,16 @@ static ModuleRep sModuleMap[] = {
 
   { "events", logging::eEvents },
   { "platforms", logging::ePlatforms },
-  { "stack", logging::eStack },
   { "text", logging::eText },
   { "tree", logging::eTree },
 
   { "DOMEvents", logging::eDOMEvents },
   { "focus", logging::eFocus },
   { "selection", logging::eSelection },
-  { "notifications", logging::eNotifications }
+  { "notifications", logging::eNotifications },
+
+  { "stack", logging::eStack },
+  { "verbose", logging::eVerbose }
 };
 
 static void
@@ -610,6 +612,61 @@ logging::SelChange(nsISelection* aSelection, DocAccessible* aDocument,
   Stack();
 }
 
+void
+logging::TreeInfo(const char* aMsg, uint32_t aExtraFlags, ...)
+{
+  if (IsEnabledAll(logging::eTree | aExtraFlags)) {
+    MsgBegin("TREE", aMsg);
+
+    va_list vl;
+    va_start(vl, aExtraFlags);
+    const char* descr = nullptr;
+    while ((descr = va_arg(vl, const char*))) {
+      AccessibleInfo(descr, va_arg(vl, Accessible*));
+    }
+    va_end(vl);
+
+    MsgEnd();
+
+    if (aExtraFlags & eStack) {
+      Stack();
+    }
+  }
+}
+
+void
+logging::TreeInfo(const char* aMsg, uint32_t aExtraFlags,
+                  const char* aMsg1, Accessible* aAcc,
+                  const char* aMsg2, nsINode* aNode)
+{
+  if (IsEnabledAll(logging::eTree | logging::eVerbose)) {
+    MsgBegin("TREE", aMsg);
+    AccessibleInfo(aMsg1, aAcc);
+    Accessible* acc = aAcc->Document()->GetAccessible(aNode);
+    if (acc) {
+      AccessibleInfo(aMsg2, acc);
+    }
+    else {
+      Node(aMsg2, aNode);
+    }
+    MsgEnd();
+  }
+}
+
+
+void
+logging::TreeInfo(const char* aMsg, uint32_t aExtraFlags, Accessible* aParent)
+{
+  if (IsEnabledAll(logging::eTree | aExtraFlags)) {
+    MsgBegin("TREE", aMsg);
+    AccessibleInfo("container", aParent);
+    for (uint32_t idx = 0; idx < aParent->ChildCount(); idx++) {
+      AccessibleInfo("child", aParent->GetChildAt(idx));
+    }
+    MsgEnd();
+  }
+}
+
 void
 logging::MsgBegin(const char* aTitle, const char* aMsgText, ...)
 {
@@ -740,6 +797,62 @@ logging::Document(DocAccessible* aDocument)
   printf("\n");
 }
 
+void
+logging::AccessibleInfo(const char* aDescr, Accessible* aAccessible)
+{
+  printf("    %s: %p; ", aDescr, static_cast<void*>(aAccessible));
+  if (!aAccessible) {
+    printf("\n");
+    return;
+  }
+  if (aAccessible->IsDefunct()) {
+    printf("defunct\n");
+    return;
+  }
+  if (!aAccessible->Document() || aAccessible->Document()->IsDefunct()) {
+    printf("document is shutting down, no info\n");
+    return;
+  }
+
+  nsAutoString role;
+  GetAccService()->GetStringRole(aAccessible->Role(), role);
+  printf("role: %s", NS_ConvertUTF16toUTF8(role).get());
+
+  nsAutoString name;
+  aAccessible->Name(name);
+  if (!name.IsEmpty()) {
+    printf(", name: '%s'", NS_ConvertUTF16toUTF8(name).get());
+  }
+
+  printf(", idx: %d", aAccessible->IndexInParent());
+
+  nsINode* node = aAccessible->GetNode();
+  if (!node) {
+    printf(", node: null\n");
+  }
+  else if (node->IsNodeOfType(nsINode::eDOCUMENT)) {
+    printf(", document node: %p\n", static_cast<void*>(node));
+  }
+  else if (node->IsNodeOfType(nsINode::eTEXT)) {
+    printf(", text node: %p\n", static_cast<void*>(node));
+  }
+  else if (node->IsElement()) {
+    dom::Element* el = node->AsElement();
+
+    nsAutoCString tag;
+    el->NodeInfo()->NameAtom()->ToUTF8String(tag);
+
+    nsIAtom* idAtom = el->GetID();
+    nsAutoCString id;
+    if (idAtom) {
+      idAtom->ToUTF8String(id);
+    }
+
+    printf(", element node: %p, %s@id='%s'\n",
+           static_cast<void*>(el), tag.get(), id.get());
+  }
+}
+
 void
 logging::AccessibleNNode(const char* aDescr, Accessible* aAccessible)
 {
@@ -818,6 +931,12 @@ logging::IsEnabled(uint32_t aModules)
   return sModules & aModules;
 }
 
+bool
+logging::IsEnabledAll(uint32_t aModules)
+{
+  return (sModules & aModules) == aModules;
+}
+
 bool
 logging::IsEnabled(const nsAString& aModuleStr)
 {
diff --git a/accessible/base/Logging.h b/accessible/base/Logging.h
index 09fc7767ee..43d0ed63c2 100644
--- a/accessible/base/Logging.h
+++ b/accessible/base/Logging.h
@@ -35,14 +35,17 @@ enum EModules {
 
   eEvents = 1 << 3,
   ePlatforms = 1 << 4,
-  eStack = 1 << 5,
-  eText = 1 << 6,
-  eTree = 1 << 7,
+  eText = 1 << 5,
+  eTree = 1 << 6,
 
-  eDOMEvents = 1 << 8,
-  eFocus = 1 << 9,
-  eSelection = 1 << 10,
-  eNotifications = eDOMEvents | eSelection | eFocus
+  eDOMEvents = 1 << 7,
+  eFocus = 1 << 8,
+  eSelection = 1 << 9,
+  eNotifications = eDOMEvents | eSelection | eFocus,
+
+  // extras
+  eStack = 1 << 10,
+  eVerbose = 1 << 11
 };
 
 /**
@@ -50,6 +53,11 @@ enum EModules {
  */
 bool IsEnabled(uint32_t aModules);
 
+/**
+ * Return true if all of the given modules are logged.
+ */
+bool IsEnabledAll(uint32_t aModules);
+
 /**
  * Return true if the given module is logged.
  */
@@ -121,6 +129,15 @@ void FocusDispatched(Accessible* aTarget);
 void SelChange(nsISelection* aSelection, DocAccessible* aDocument,
                int16_t aReason);
 
+/**
+ * Log the given accessible elements info.
+ */
+void TreeInfo(const char* aMsg, uint32_t aExtraFlags, ...);
+void TreeInfo(const char* aMsg, uint32_t aExtraFlags,
+              const char* aMsg1, Accessible* aAcc,
+              const char* aMsg2, nsINode* aNode);
+void TreeInfo(const char* aMsg, uint32_t aExtraFlags, Accessible* aParent);
+
 /**
  * Log the message ('title: text' format) on new line. Print the start and end
  * boundaries of the message body designated by '{' and '}' (2 spaces indent for
@@ -164,6 +181,7 @@ void Document(DocAccessible* aDocument);
 /**
  * Log the accessible and its DOM node as a message entry.
  */
+void AccessibleInfo(const char* aDescr, Accessible* aAccessible);
 void AccessibleNNode(const char* aDescr, Accessible* aAccessible);
 void AccessibleNNode(const char* aDescr, nsINode* aNode);
 
@@ -189,7 +207,8 @@ void Enable(const nsAFlatCString& aModules);
  */
 void CheckEnv();
 
-} // namespace logs
+} // namespace logging
+
 } // namespace a11y
 } // namespace mozilla
 
diff --git a/accessible/base/TreeWalker.cpp b/accessible/base/TreeWalker.cpp
index de3d155469..79ad5c9269 100644
--- a/accessible/base/TreeWalker.cpp
+++ b/accessible/base/TreeWalker.cpp
@@ -21,18 +21,33 @@ using namespace mozilla::a11y;
 ////////////////////////////////////////////////////////////////////////////////
 
 TreeWalker::
-  TreeWalker(Accessible* aContext, nsIContent* aContent, uint32_t aFlags) :
-  mDoc(aContext->Document()), mContext(aContext), mAnchorNode(aContent),
-  mFlags(aFlags)
+  TreeWalker(Accessible* aContext) :
+  mDoc(aContext->Document()), mContext(aContext), mAnchorNode(nullptr),
+  mARIAOwnsIdx(0),
+  mChildFilter(nsIContent::eSkipPlaceholderContent), mFlags(0),
+  mPhase(eAtStart)
 {
-  NS_ASSERTION(aContent, "No node for the accessible tree walker!");
-
-  mChildFilter = mContext->NoXBLKids() ?
+  mChildFilter |= mContext->NoXBLKids() ?
     nsIContent::eAllButXBL : nsIContent::eAllChildren;
-  mChildFilter |= nsIContent::eSkipPlaceholderContent;
 
-  if (aContent)
-    PushState(aContent);
+  mAnchorNode = mContext->IsDoc() ?
+    mDoc->DocumentNode()->GetRootElement() : mContext->GetContent();
+
+  MOZ_COUNT_CTOR(TreeWalker);
+}
+
+TreeWalker::
+  TreeWalker(Accessible* aContext, nsIContent* aAnchorNode, uint32_t aFlags) :
+  mDoc(aContext->Document()), mContext(aContext), mAnchorNode(aAnchorNode),
+  mARIAOwnsIdx(0),
+  mChildFilter(nsIContent::eSkipPlaceholderContent), mFlags(aFlags),
+  mPhase(eAtStart)
+{
+  MOZ_ASSERT(mFlags & eWalkCache, "This constructor cannot be used for tree creation");
+  MOZ_ASSERT(aAnchorNode, "No anchor node for the accessible tree walker");
+
+  mChildFilter |= mContext->NoXBLKids() ?
+    nsIContent::eAllButXBL : nsIContent::eAllChildren;
 
   MOZ_COUNT_CTOR(TreeWalker);
 }
@@ -42,35 +57,122 @@ TreeWalker::~TreeWalker()
   MOZ_COUNT_DTOR(TreeWalker);
 }
 
-////////////////////////////////////////////////////////////////////////////////
-// TreeWalker: private
-
-Accessible*
-TreeWalker::Next()
+bool
+TreeWalker::Seek(nsIContent* aChildNode)
 {
-  if (mStateStack.IsEmpty())
-    return nullptr;
+  MOZ_ASSERT(aChildNode, "Child cannot be null");
 
-  ChildrenIterator* top = &mStateStack[mStateStack.Length() - 1];
-  while (top) {
-    Accessible* child = nullptr;
-    bool skipSubtree = false;
-    while (nsIContent* childNode = Next(top, &child, &skipSubtree)) {
-      if (child)
-        return child;
+  mPhase = eAtStart;
+  mStateStack.Clear();
+  mARIAOwnsIdx = 0;
 
-      // Walk down into subtree to find accessibles.
-      if (!skipSubtree && childNode->IsElement())
-        top = PushState(childNode);
+  nsIContent* childNode = nullptr;
+  nsINode* parentNode = aChildNode;
+  do {
+    childNode = parentNode->AsContent();
+    parentNode = childNode->HasFlag(NODE_MAY_BE_IN_BINDING_MNGR) &&
+      (mChildFilter & nsIContent::eAllButXBL) ?
+      childNode->GetParentNode() : childNode->GetFlattenedTreeParent();
+
+    if (!parentNode || !parentNode->IsElement()) {
+      return false;
     }
 
+    // If ARIA owned child.
+    Accessible* child = mDoc->GetAccessible(childNode);
+    if (child && child->IsRelocated()) {
+      if (child->Parent() != mContext) {
+        return false;
+      }
+
+      Accessible* ownedChild = nullptr;
+      while ((ownedChild = mDoc->ARIAOwnedAt(mContext, mARIAOwnsIdx++)) &&
+             ownedChild != child);
+
+      MOZ_ASSERT(ownedChild, "A child has to be in ARIA owned elements");
+      mPhase = eAtARIAOwns;
+      return true;
+    }
+
+    // Look in DOM.
+    dom::AllChildrenIterator* iter = PrependState(parentNode->AsElement(), true);
+    if (!iter->Seek(childNode)) {
+      return false;
+    }
+
+    if (parentNode == mAnchorNode) {
+      mPhase = eAtDOM;
+      return true;
+    }
+  } while (true);
+
+  return false;
+}
+
+Accessible*
+TreeWalker::Next(nsIContent* aStopNode)
+{
+  if (mStateStack.IsEmpty()) {
+    if (mPhase == eAtEnd) {
+      return nullptr;
+    }
+
+    if (mPhase == eAtDOM || mPhase == eAtARIAOwns) {
+      mPhase = eAtARIAOwns;
+      Accessible* child = mDoc->ARIAOwnedAt(mContext, mARIAOwnsIdx);
+      if (child) {
+        mARIAOwnsIdx++;
+        return child;
+      }
+      mPhase = eAtEnd;
+      return nullptr;
+    }
+
+    if (!mAnchorNode) {
+      mPhase = eAtEnd;
+      return nullptr;
+    }
+
+    mPhase = eAtDOM;
+    PushState(mAnchorNode, true);
+  }
+
+  dom::AllChildrenIterator* top = &mStateStack[mStateStack.Length() - 1];
+  while (top) {
+    if (aStopNode && top->Get() == aStopNode) {
+      return nullptr;
+    }
+
+    while (nsIContent* childNode = top->GetNextChild()) {
+      bool skipSubtree = false;
+      Accessible* child = AccessibleFor(childNode, mFlags, &skipSubtree);
+      if (child) {
+        return child;
+      }
+
+      // Walk down the subtree if allowed, otherwise check if we have reached
+      // a stop node.
+      if (!skipSubtree && childNode->IsElement()) {
+        top = PushState(childNode, true);
+      }
+      else if (childNode == aStopNode) {
+        return nullptr;
+      }
+    }
     top = PopState();
   }
 
   // If we traversed the whole subtree of the anchor node. Move to next node
-  // relative anchor node within the context subtree if possible.
-  if (mFlags != eWalkContextTree)
-    return nullptr;
+  // relative anchor node within the context subtree if asked.
+  if (mFlags != eWalkContextTree) {
+    // eWalkCache flag presence indicates that the search is scoped to the
+    // anchor (no ARIA owns stuff).
+    if (mFlags & eWalkCache) {
+      mPhase = eAtEnd;
+      return nullptr;
+    }
+    return Next(aStopNode);
+  }
 
   nsINode* contextNode = mContext->GetNode();
   while (mAnchorNode != contextNode) {
@@ -79,10 +181,10 @@ TreeWalker::Next()
       return nullptr;
 
     nsIContent* parent = parentNode->AsElement();
-    top = PushState(parent);
-    if (top->mDOMIter.Seek(mAnchorNode)) {
+    top = PushState(parent, true);
+    if (top->Seek(mAnchorNode)) {
       mAnchorNode = parent;
-      return Next();
+      return Next(aStopNode);
     }
 
     // XXX We really should never get here, it means we're trying to find an
@@ -92,58 +194,110 @@ TreeWalker::Next()
     mAnchorNode = parent;
   }
 
-  return nullptr;
+  return Next(aStopNode);
 }
 
-nsIContent*
-TreeWalker::Next(ChildrenIterator* aIter, Accessible** aAccesible,
-                 bool* aSkipSubtree)
+Accessible*
+TreeWalker::Prev()
 {
-  nsIContent* childEl = aIter->mDOMIter.GetNextChild();
-  if (!aAccesible)
-    return childEl;
-
-  *aAccesible = nullptr;
-  *aSkipSubtree = false;
-
-  if (childEl) {
-    Accessible* accessible = nullptr;
-    if (mFlags & eWalkCache) {
-      accessible = mDoc->GetAccessible(childEl);
-    }
-    else if (mContext->IsAcceptableChild(childEl)) {
-      accessible = GetAccService()->
-        GetOrCreateAccessible(childEl, mContext, aSkipSubtree);
+  if (mStateStack.IsEmpty()) {
+    if (mPhase == eAtStart || mPhase == eAtDOM) {
+      mPhase = eAtStart;
+      return nullptr;
     }
 
-    // Ignore the accessible and its subtree if it was repositioned by means of
-    // aria-owns.
-    if (accessible) {
-      if (accessible->IsRelocated()) {
-        *aSkipSubtree = true;
-      } else {
-        *aAccesible = accessible;
+    if (mPhase == eAtEnd) {
+      mARIAOwnsIdx = mDoc->ARIAOwnedCount(mContext);
+      mPhase = eAtARIAOwns;
+    }
+
+    if (mPhase == eAtARIAOwns) {
+      if (mARIAOwnsIdx > 0) {
+        return mDoc->ARIAOwnedAt(mContext, --mARIAOwnsIdx);
+      }
+
+      if (!mAnchorNode) {
+        mPhase = eAtStart;
+        return nullptr;
+      }
+
+      mPhase = eAtDOM;
+      PushState(mAnchorNode, false);
+    }
+  }
+
+  dom::AllChildrenIterator* top = &mStateStack[mStateStack.Length() - 1];
+  while (top) {
+    while (nsIContent* childNode = top->GetPreviousChild()) {
+      // No accessible creation on the way back.
+      bool skipSubtree = false;
+      Accessible* child = AccessibleFor(childNode, eWalkCache, &skipSubtree);
+      if (child) {
+        return child;
+      }
+
+      // Walk down into subtree to find accessibles.
+      if (!skipSubtree && childNode->IsElement()) {
+        top = PushState(childNode, false);
       }
     }
-    return childEl;
+    top = PopState();
   }
 
-  // At last iterate over ARIA owned children.
-  Accessible* parent = mDoc->GetAccessible(aIter->mDOMIter.Parent());
-  if (parent) {
-    Accessible* child = mDoc->ARIAOwnedAt(parent, aIter->mARIAOwnsIdx++);
-    if (child) {
-      *aAccesible = child;
-      return child->GetContent();
-    }
+  // Move to a previous node relative the anchor node within the context
+  // subtree if asked.
+  if (mFlags != eWalkContextTree) {
+    mPhase = eAtStart;
+    return nullptr;
   }
+
+  nsINode* contextNode = mContext->GetNode();
+  while (mAnchorNode != contextNode) {
+    nsINode* parentNode = mAnchorNode->GetFlattenedTreeParent();
+    if (!parentNode || !parentNode->IsElement()) {
+      return nullptr;
+    }
+
+    nsIContent* parent = parentNode->AsElement();
+    top = PushState(parent, true);
+    if (top->Seek(mAnchorNode)) {
+      mAnchorNode = parent;
+      return Prev();
+    }
+
+    mAnchorNode = parent;
+  }
+
+  mPhase = eAtStart;
   return nullptr;
 }
 
-TreeWalker::ChildrenIterator*
+Accessible*
+TreeWalker::AccessibleFor(nsIContent* aNode, uint32_t aFlags, bool* aSkipSubtree)
+{
+  Accessible* child = nullptr;
+  if (aFlags & eWalkCache) {
+    child = mDoc->GetAccessible(aNode);
+  }
+  else if (mContext->IsAcceptableChild(aNode)) {
+    child = GetAccService()->
+      GetOrCreateAccessible(aNode, mContext, aSkipSubtree);
+  }
+
+  // Ignore the accessible and its subtree if it was repositioned by means
+  // of aria-owns.
+  if (child && child->IsRelocated()) {
+    *aSkipSubtree = true;
+    return nullptr;
+  }
+
+  return child;
+}
+
+dom::AllChildrenIterator*
 TreeWalker::PopState()
 {
   size_t length = mStateStack.Length();
   mStateStack.RemoveElementAt(length - 1);
-  return mStateStack.IsEmpty() ? nullptr : &mStateStack[mStateStack.Length() - 1];
+  return mStateStack.IsEmpty() ? nullptr : &mStateStack.LastElement();
 }
diff --git a/accessible/base/TreeWalker.h b/accessible/base/TreeWalker.h
index d35c8147ce..afce61789f 100644
--- a/accessible/base/TreeWalker.h
+++ b/accessible/base/TreeWalker.h
@@ -33,63 +33,94 @@ public:
   };
 
   /**
-   * Constructor
+   * Used to navigate and create if needed the accessible children.
+   */
+  explicit TreeWalker(Accessible* aContext);
+
+  /**
+   * Used to navigate the accessible children relative to the anchor.
    *
    * @param aContext [in] container accessible for the given node, used to
    *                   define accessible context
-   * @param aNode    [in] the node the search will be prepared relative to
+   * @param aAnchorNode [in] the node the search will be prepared relative to
    * @param aFlags   [in] flags (see enum above)
    */
-  TreeWalker(Accessible* aContext, nsIContent* aNode, uint32_t aFlags = 0);
+  TreeWalker(Accessible* aContext, nsIContent* aAnchorNode, uint32_t aFlags = eWalkCache);
+
   ~TreeWalker();
 
   /**
-   * Return the next accessible.
+   * Clears the tree walker state and resets it to the given child within
+   * the anchor.
+   */
+  bool Seek(nsIContent* aChildNode);
+
+  /**
+   * Return the next/prev accessible.
    *
    * @note Returned accessible is bound to the document, if the accessible is
    *       rejected during tree creation then the caller should be unbind it
    *       from the document.
    */
-  Accessible* Next();
+  Accessible* Next(nsIContent* aStopNode = nullptr);
+  Accessible* Prev();
+
+  Accessible* Context() const { return mContext; }
+  DocAccessible* Document() const { return mDoc; }
 
 private:
   TreeWalker();
   TreeWalker(const TreeWalker&);
   TreeWalker& operator =(const TreeWalker&);
 
-  struct ChildrenIterator {
-    ChildrenIterator(nsIContent* aNode, uint32_t aFilter) :
-      mDOMIter(aNode, aFilter), mARIAOwnsIdx(0) { }
-
-    dom::AllChildrenIterator mDOMIter;
-    uint32_t mARIAOwnsIdx;
-  };
-
-  nsIContent* Next(ChildrenIterator* aIter, Accessible** aAccessible = nullptr,
-                   bool* aSkipSubtree = nullptr);
+  /**
+   * Return an accessible for the given node if any.
+   */
+  Accessible* AccessibleFor(nsIContent* aNode, uint32_t aFlags,
+                            bool* aSkipSubtree);
 
   /**
-   * Create new state for the given node and push it on top of stack.
+   * Create new state for the given node and push it on top of stack / at bottom
+   * of stack.
    *
    * @note State stack is used to navigate up/down the DOM subtree during
    *        accessible children search.
    */
-  ChildrenIterator* PushState(nsIContent* aContent)
+  dom::AllChildrenIterator* PushState(nsIContent* aContent,
+                                      bool aStartAtBeginning)
   {
-    return mStateStack.AppendElement(ChildrenIterator(aContent, mChildFilter));
+    return mStateStack.AppendElement(
+      dom::AllChildrenIterator(aContent, mChildFilter, aStartAtBeginning));
+  }
+  dom::AllChildrenIterator* PrependState(nsIContent* aContent,
+                                         bool aStartAtBeginning)
+  {
+    return mStateStack.InsertElementAt(0,
+      dom::AllChildrenIterator(aContent, mChildFilter, aStartAtBeginning));
   }
 
   /**
    * Pop state from stack.
    */
-  ChildrenIterator* PopState();
+  dom::AllChildrenIterator* PopState();
 
   DocAccessible* mDoc;
   Accessible* mContext;
   nsIContent* mAnchorNode;
-  AutoTArray<ChildrenIterator, 20> mStateStack;
+
+  AutoTArray<dom::AllChildrenIterator, 20> mStateStack;
+  uint32_t mARIAOwnsIdx;
+
   int32_t mChildFilter;
   uint32_t mFlags;
+
+  enum Phase {
+    eAtStart,
+    eAtDOM,
+    eAtARIAOwns,
+    eAtEnd
+  };
+  Phase mPhase;
 };
 
 } // namespace a11y
diff --git a/accessible/generic/Accessible.cpp b/accessible/generic/Accessible.cpp
index 7bc1732c6f..2338221471 100644
--- a/accessible/generic/Accessible.cpp
+++ b/accessible/generic/Accessible.cpp
@@ -1983,6 +1983,10 @@ Accessible::BindToParent(Accessible* aParent, uint32_t aIndexInParent)
 
   if (mParent->IsARIAHidden() || aria::HasDefinedARIAHidden(mContent))
     SetARIAHidden(true);
+
+  mContextFlags |=
+    static_cast<uint32_t>((mParent->IsAlert() ||
+                           mParent->IsInsideAlert())) & eInsideAlert;
 }
 
 // Accessible protected
@@ -2000,7 +2004,7 @@ Accessible::UnbindFromParent()
 
   delete mBits.groupInfo;
   mBits.groupInfo = nullptr;
-  mContextFlags &= ~eHasNameDependentParent;
+  mContextFlags &= ~eHasNameDependentParent & ~eInsideAlert;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -2542,10 +2546,9 @@ Accessible::LastRelease()
 void
 Accessible::CacheChildren()
 {
-  DocAccessible* doc = Document();
-  NS_ENSURE_TRUE_VOID(doc);
+  NS_ENSURE_TRUE_VOID(Document());
 
-  TreeWalker walker(this, mContent);
+  TreeWalker walker(this);
 
   Accessible* child = nullptr;
   while ((child = walker.Next()) && AppendChild(child));
diff --git a/accessible/generic/Accessible.h b/accessible/generic/Accessible.h
index 5becdd2a64..f6992439d9 100644
--- a/accessible/generic/Accessible.h
+++ b/accessible/generic/Accessible.h
@@ -568,6 +568,8 @@ public:
     return mContent->IsAnyOfHTMLElements(nsGkAtoms::abbr, nsGkAtoms::acronym);
   }
 
+  bool IsAlert() const { return HasGenericType(eAlert); }
+
   bool IsApplication() const { return mType == eApplicationType; }
   ApplicationAccessible* AsApplication();
 
@@ -946,6 +948,11 @@ public:
   bool IsARIAHidden() const { return mContextFlags & eARIAHidden; }
   void SetARIAHidden(bool aIsDefined);
 
+  /**
+   * Return true if the element is inside an alert.
+   */
+  bool IsInsideAlert() const { return mContextFlags & eInsideAlert; }
+
 protected:
   virtual ~Accessible();
 
@@ -1034,8 +1041,9 @@ protected:
   enum ContextFlags {
     eHasNameDependentParent = 1 << 0, // Parent's name depends on this accessible.
     eARIAHidden = 1 << 1,
+    eInsideAlert = 1 << 2,
 
-    eLastContextFlag = eARIAHidden
+    eLastContextFlag = eInsideAlert
   };
 
 protected:
@@ -1141,9 +1149,9 @@ protected:
 
   static const uint8_t kChildrenFlagsBits = 2;
   static const uint8_t kStateFlagsBits = 11;
-  static const uint8_t kContextFlagsBits = 2;
+  static const uint8_t kContextFlagsBits = 3;
   static const uint8_t kTypeBits = 6;
-  static const uint8_t kGenericTypesBits = 14;
+  static const uint8_t kGenericTypesBits = 15;
 
   /**
    * Keep in sync with ChildrenFlags, StateFlags, ContextFlags, and AccTypes.
diff --git a/accessible/generic/DocAccessible.cpp b/accessible/generic/DocAccessible.cpp
index d20d1844a4..5b56e411a4 100644
--- a/accessible/generic/DocAccessible.cpp
+++ b/accessible/generic/DocAccessible.cpp
@@ -1421,36 +1421,6 @@ if (!aNode->IsContent() || !aNode->AsContent()->IsHTMLElement(nsGkAtoms::area))
   return GetAccessible(aNode);
 }
 
-////////////////////////////////////////////////////////////////////////////////
-// Accessible protected
-
-void
-DocAccessible::CacheChildren()
-{
-  // Search for accessible children starting from the document element since
-  // some web pages tend to insert elements under it rather than document body.
-  dom::Element* rootElm = mDocumentNode->GetRootElement();
-  if (!rootElm)
-    return;
-
-  // Ignore last HTML:br, copied from HyperTextAccessible.
-  TreeWalker walker(this, rootElm);
-  Accessible* lastChild = nullptr;
-  while (Accessible* child = walker.Next()) {
-    if (lastChild)
-      AppendChild(lastChild);
-
-    lastChild = child;
-  }
-
-  if (lastChild) {
-    if (lastChild->IsHTMLBr())
-      Document()->UnbindFromDocument(lastChild);
-    else
-      AppendChild(lastChild);
-  }
-}
-
 ////////////////////////////////////////////////////////////////////////////////
 // Protected members
 
@@ -1786,22 +1756,16 @@ DocAccessible::UpdateTreeOnInsertion(Accessible* aContainer)
 
   // Check to see if change occurred inside an alert, and fire an EVENT_ALERT
   // if it did.
-  if (!(updateFlags & eAlertAccessible)) {
-    // XXX: tree traversal is perf issue, accessible should know if they are
-    // children of alert accessible to avoid this.
+  if (!(updateFlags & eAlertAccessible) &&
+      (aContainer->IsAlert() || aContainer->IsInsideAlert())) {
     Accessible* ancestor = aContainer;
-    while (ancestor) {
-      if (ancestor->ARIARole() == roles::ALERT) {
+    do {
+      if (ancestor->IsAlert()) {
         FireDelayedEvent(nsIAccessibleEvent::EVENT_ALERT, ancestor);
         break;
       }
-
-      // Don't climb above this document.
-      if (ancestor == this)
-        break;
-
-      ancestor = ancestor->Parent();
     }
+    while ((ancestor = ancestor->Parent()));
   }
 
   MaybeNotifyOfValueChange(aContainer);
@@ -1834,34 +1798,9 @@ DocAccessible::UpdateTreeOnRemoval(Accessible* aContainer, nsIContent* aChildNod
   if (child) {
     updateFlags |= UpdateTreeInternal(child, false, reorderEvent);
   } else {
-    // aChildNode may not coorespond to a particular accessible, to handle
-    // this we go through all the children of aContainer.  Then if a child
-    // has aChildNode as an ancestor, or does not have the node for
-    // aContainer as an ancestor remove that child of aContainer.  Note that
-    // when we are called aChildNode may already have been removed from the DOM
-    // so we can't expect it to have a parent or what was it's parent to have
-    // it as a child.
-    nsINode* containerNode = aContainer->GetNode();
-    for (uint32_t idx = 0; idx < aContainer->ContentChildCount();) {
-      Accessible* child = aContainer->ContentChildAt(idx);
-
-      // If accessible doesn't have its own content then we assume parent
-      // will handle its update.  If child is DocAccessible then we don't
-      // handle updating it here either.
-      if (!child->HasOwnContent() || child->IsDoc()) {
-        idx++;
-        continue;
-      }
-
-      nsINode* childNode = child->GetContent();
-      while (childNode != aChildNode && childNode != containerNode &&
-             (childNode = childNode->GetParentNode()));
-
-      if (childNode != containerNode) {
-        updateFlags |= UpdateTreeInternal(child, false, reorderEvent);
-      } else {
-        idx++;
-      }
+    TreeWalker walker(aContainer, aChildNode, TreeWalker::eWalkCache);
+    while (Accessible* child = walker.Next()) {
+      updateFlags |= UpdateTreeInternal(child, false, reorderEvent);
     }
   }
 
@@ -2057,6 +1996,7 @@ DocAccessible::DoARIAOwnsRelocation(Accessible* aOwner)
       MoveChild(child, insertIdx);
       children->InsertElementAt(arrayIdx, child);
       arrayIdx++;
+      insertIdx = child->IndexInParent() + 1;
 
     } else if (SeizeChild(aOwner, child, insertIdx)) {
       children->InsertElementAt(arrayIdx, child);
@@ -2083,6 +2023,12 @@ DocAccessible::SeizeChild(Accessible* aNewParent, Accessible* aChild,
 
   int32_t oldIdxInParent = aChild->IndexInParent();
 
+#ifdef A11Y_LOG
+  logging::TreeInfo("aria owns seize child", 0,
+                    "old parent", oldParent, "new parent", aNewParent,
+                    "child", aChild, nullptr);
+#endif
+
   RefPtr<AccReorderEvent> reorderEvent = new AccReorderEvent(oldParent);
   RefPtr<AccMutationEvent> hideEvent = new AccHideEvent(aChild, false);
   reorderEvent->AddSubMutationEvent(hideEvent);
@@ -2098,6 +2044,11 @@ DocAccessible::SeizeChild(Accessible* aNewParent, Accessible* aChild,
     isReinserted = aNewParent->InsertChildAt(aIdxInParent, aChild);
   }
 
+#ifdef A11Y_LOG
+    logging::TreeInfo("aria owns seize child: new parent tree after",
+                      logging::eVerbose, aNewParent);
+#endif
+
   if (!isReinserted) {
     AutoTreeMutation mut(oldParent);
     oldParent->InsertChildAt(oldIdxInParent, aChild);
@@ -2136,10 +2087,20 @@ DocAccessible::MoveChild(Accessible* aChild, int32_t aIdxInParent)
   RefPtr<AccMutationEvent> hideEvent = new AccHideEvent(aChild, false);
   reorderEvent->AddSubMutationEvent(hideEvent);
 
+#ifdef A11Y_LOG
+  logging::TreeInfo("aria owns move child", 0,
+                    "parent", parent, "child", aChild, nullptr);
+#endif
+
   AutoTreeMutation mut(parent);
   parent->MoveChild(aIdxInParent, aChild);
   aChild->SetRelocated(true);
 
+#ifdef A11Y_LOG
+  logging::TreeInfo("aria owns move child: parent tree after",
+                    logging::eVerbose, parent);
+#endif
+
   FireDelayedEvent(hideEvent);
 
   RefPtr<AccMutationEvent> showEvent = new AccShowEvent(aChild);
diff --git a/accessible/generic/DocAccessible.h b/accessible/generic/DocAccessible.h
index 8a5e5ae90e..5bd62e4f12 100644
--- a/accessible/generic/DocAccessible.h
+++ b/accessible/generic/DocAccessible.h
@@ -291,6 +291,11 @@ public:
     }
     return nullptr;
   }
+  uint32_t ARIAOwnedCount(Accessible* aParent) const
+  {
+    nsTArray<RefPtr<Accessible> >* children = mARIAOwnsHash.Get(aParent);
+    return children ? children->Length() : 0;
+  }
 
   /**
    * Return true if the given ID is referred by relation attribute.
@@ -359,9 +364,6 @@ protected:
 
   void LastRelease();
 
-  // Accessible
-  virtual void CacheChildren() override;
-
   // DocAccessible
   virtual nsresult AddEventListeners();
   virtual nsresult RemoveEventListeners();
diff --git a/accessible/generic/HyperTextAccessible.cpp b/accessible/generic/HyperTextAccessible.cpp
index 751211668a..e6bc7e0830 100644
--- a/accessible/generic/HyperTextAccessible.cpp
+++ b/accessible/generic/HyperTextAccessible.cpp
@@ -1935,31 +1935,6 @@ HyperTextAccessible::RelationByType(RelationType aType)
   return rel;
 }
 
-void
-HyperTextAccessible::CacheChildren()
-{
-  // Trailing HTML br element don't play any difference. We don't need to expose
-  // it to AT (see bug https://bugzilla.mozilla.org/show_bug.cgi?id=899433#c16
-  // for details).
-
-  TreeWalker walker(this, mContent);
-  Accessible* child = nullptr;
-  Accessible* lastChild = nullptr;
-  while ((child = walker.Next())) {
-    if (lastChild)
-      AppendChild(lastChild);
-
-    lastChild = child;
-  }
-
-  if (lastChild) {
-    if (lastChild->IsHTMLBr())
-      Document()->UnbindFromDocument(lastChild);
-    else
-      AppendChild(lastChild);
-  }
-}
-
 ////////////////////////////////////////////////////////////////////////////////
 // HyperTextAccessible public static
 
diff --git a/accessible/generic/HyperTextAccessible.h b/accessible/generic/HyperTextAccessible.h
index 4d6e39f608..25fcfb8154 100644
--- a/accessible/generic/HyperTextAccessible.h
+++ b/accessible/generic/HyperTextAccessible.h
@@ -434,7 +434,6 @@ protected:
 
   // Accessible
   virtual ENameValueFlag NativeName(nsString& aName) override;
-  virtual void CacheChildren() override;
 
   // HyperTextAccessible
 
diff --git a/accessible/tests/mochitest/common.js b/accessible/tests/mochitest/common.js
index 842af97d03..0c591e5003 100644
--- a/accessible/tests/mochitest/common.js
+++ b/accessible/tests/mochitest/common.js
@@ -126,9 +126,23 @@ function dumpTree(aId, aMsg)
     }
   }
 
+  function dumpDOMTreeIntl(node, indent)
+  {
+    dump(indent + prettyName(node) + "\n");
+
+    var children = node.childNodes;
+    for (var i = 0; i < children.length; i++) {
+      var child = children.item(i);
+      dumpDOMTreeIntl(child, indent + "  ");
+    }
+  }
+
   dump(aMsg + "\n");
   var root = getAccessible(aId);
   dumpTreeIntl(root, "  ");
+
+  dump("DOM tree:\n");
+  dumpDOMTreeIntl(getNode(aId), "  ");
 }
 
 /**
diff --git a/accessible/tests/mochitest/editabletext/editabletext.js b/accessible/tests/mochitest/editabletext/editabletext.js
index ce2f9ebd27..5c4470782b 100644
--- a/accessible/tests/mochitest/editabletext/editabletext.js
+++ b/accessible/tests/mochitest/editabletext/editabletext.js
@@ -62,6 +62,7 @@ function editableTextTest(aID)
 
     function setTextContentsInvoke()
     {
+      dump(`\nsetTextContents '${aValue}'\n`);
       var acc = getAccessible(aID, nsIAccessibleEditableText);
       acc.setTextContents(aValue);
     }
@@ -84,6 +85,7 @@ function editableTextTest(aID)
 
     function insertTextInvoke()
     {
+      dump(`\ninsertText '${aStr}' at ${aPos} pos\n`);
       var acc = getAccessible(aID, nsIAccessibleEditableText);
       acc.insertText(aStr, aPos);
     }
diff --git a/accessible/tests/mochitest/events/test_aria_menu.html b/accessible/tests/mochitest/events/test_aria_menu.html
index d6b99b9376..2dd00478e5 100644
--- a/accessible/tests/mochitest/events/test_aria_menu.html
+++ b/accessible/tests/mochitest/events/test_aria_menu.html
@@ -153,6 +153,7 @@
     var gQueue = null;
 
     //gA11yEventDumpToConsole = true; // debuging
+    //enableLogging("tree,verbose");
 
     function doTests()
     {
diff --git a/accessible/tests/mochitest/treeupdate/test_ariaowns.html b/accessible/tests/mochitest/treeupdate/test_ariaowns.html
index 2070136f1b..abe88c3841 100644
--- a/accessible/tests/mochitest/treeupdate/test_ariaowns.html
+++ b/accessible/tests/mochitest/treeupdate/test_ariaowns.html
@@ -441,12 +441,81 @@
       }
     }
 
+    function rearrangeARIAOwns(aContainer, aAttr, aIdList, aRoleList)
+    {
+      this.eventSeq = [];
+      for (var id of aIdList) {
+        this.eventSeq.push(new invokerChecker(EVENT_HIDE, getNode(id)));
+        this.eventSeq.push(new invokerChecker(EVENT_SHOW, getNode(id)));
+      }
+      this.eventSeq.push(new invokerChecker(EVENT_REORDER, getNode(aContainer)));
+
+      this.invoke = function rearrangeARIAOwns_invoke()
+      {
+        getNode(aContainer).setAttribute("aria-owns", aAttr);
+      }
+
+      this.finalCheck = function rearrangeARIAOwns_finalCheck()
+      {
+        var tree = { SECTION: [ ] };
+        for (var role of aRoleList) {
+          var ch = {};
+          ch[role] = [];
+          tree["SECTION"].push(ch);
+        }
+        testAccessibleTree(aContainer, tree);
+      }
+
+      this.getID = function rearrangeARIAOwns_getID()
+      {
+        return `Rearrange @aria-owns attribute to '${aAttr}'`;
+      }
+    }
+
+    function removeNotARIAOwnedEl(aContainer, aChild)
+    {
+      this.eventSeq = [
+        new invokerChecker(EVENT_REORDER, aContainer)
+      ];
+
+      this.invoke = function removeNotARIAOwnedEl_invoke()
+      {
+        dumpTree(aContainer, "before");
+        var tree = {
+          SECTION: [
+            { TEXT_LEAF: [ ] },
+            { GROUPING: [ ] }
+          ]
+        };
+        testAccessibleTree(aContainer, tree);
+
+        getNode(aContainer).removeChild(getNode(aChild));
+      }
+
+      this.finalCheck = function removeNotARIAOwnedEl_finalCheck()
+      {
+        dumpTree(aContainer, "after");
+        var tree = {
+          SECTION: [
+            { GROUPING: [ ] }
+          ]
+        };
+        testAccessibleTree(aContainer, tree);
+      }
+
+      this.getID = function removeNotARIAOwnedEl_getID()
+      {
+        return `remove not ARIA owned child`;
+      }
+    }
+
+
     ////////////////////////////////////////////////////////////////////////////
     // Test
     ////////////////////////////////////////////////////////////////////////////
 
     //gA11yEventDumpToConsole = true;
-    //enableLogging("tree"); // debug stuff
+    //enableLogging("tree,verbose"); // debug stuff
 
     var gQueue = null;
 
@@ -474,6 +543,18 @@
       // test4
       gQueue.push(new showHiddenElement());
 
+      // test5
+      gQueue.push(new rearrangeARIAOwns(
+        "t5_container", "t5_checkbox t5_radio t5_button",
+        [ "t5_checkbox", "t5_radio", "t5_button" ],
+        [ "CHECKBUTTON", "RADIOBUTTON", "PUSHBUTTON" ]));
+      gQueue.push(new rearrangeARIAOwns(
+        "t5_container", "t5_radio t5_button t5_checkbox",
+        [ "t5_radio", "t5_button" ],
+        [ "RADIOBUTTON", "PUSHBUTTON", "CHECKBUTTON" ]));
+
+      gQueue.push(new removeNotARIAOwnedEl("t6_container", "t6_span"));
+
       gQueue.invoke(); // SimpleTest.finish() will be called in the end
     }
 
@@ -515,6 +596,17 @@
     <div id="t4_child1" style="display:none" role="checkbox"></div>
     <div id="t4_child2" role="radio"></div>
   </div>
+
+  <div id="t5_container">
+    <div role="button" id="t5_button"></div>
+    <div role="checkbox" id="t5_checkbox"></div>
+    <div role="radio" id="t5_radio"></div>
+  </div>
+
+  <div id="t6_container" aria-owns="t6_fake">
+    <span id="t6_span">hey</span>
+  </div>
+  <div id="t6_fake" role="group"></div>
 </body>
 
 </html>
diff --git a/accessible/xul/XULAlertAccessible.cpp b/accessible/xul/XULAlertAccessible.cpp
index 394904a733..4b1b5bd8d8 100644
--- a/accessible/xul/XULAlertAccessible.cpp
+++ b/accessible/xul/XULAlertAccessible.cpp
@@ -19,6 +19,7 @@ XULAlertAccessible::
   XULAlertAccessible(nsIContent* aContent, DocAccessible* aDoc) :
   AccessibleWrap(aContent, aDoc)
 {
+  mGenericTypes |= eAlert;
 }
 
 XULAlertAccessible::~XULAlertAccessible()
diff --git a/b2g/components/AboutServiceWorkers.jsm b/b2g/components/AboutServiceWorkers.jsm
index 4c36bb1c63..1fd3e458d1 100644
--- a/b2g/components/AboutServiceWorkers.jsm
+++ b/b2g/components/AboutServiceWorkers.jsm
@@ -29,17 +29,12 @@ function serializeServiceWorkerInfo(aServiceWorkerInfo) {
 
   let result = {};
 
-  Object.keys(aServiceWorkerInfo).forEach(property => {
-    if (typeof aServiceWorkerInfo[property] == "function") {
-      return;
-    }
-    if (property === "principal") {
-      result.principal = {
-        origin: aServiceWorkerInfo.principal.origin,
-        originAttributes: aServiceWorkerInfo.principal.originAttributes
-      };
-      return;
-    }
+  result.principal = {
+    origin: aServiceWorkerInfo.principal.originNoSuffix,
+    originAttributes: aServiceWorkerInfo.principal.originAttributes
+  };
+
+  ["scope", "scriptSpec"].forEach(property => {
     result[property] = aServiceWorkerInfo[property];
   });
 
diff --git a/b2g/components/ContentPermissionPrompt.js b/b2g/components/ContentPermissionPrompt.js
index 138e8368b2..4edf7d3841 100644
--- a/b2g/components/ContentPermissionPrompt.js
+++ b/b2g/components/ContentPermissionPrompt.js
@@ -32,7 +32,7 @@ Cu.import("resource://gre/modules/PermissionsTable.jsm");
 var permissionManager = Cc["@mozilla.org/permissionmanager;1"].getService(Ci.nsIPermissionManager);
 var secMan = Cc["@mozilla.org/scriptsecuritymanager;1"].getService(Ci.nsIScriptSecurityManager);
 
-let permissionSpecificChecker = {};
+var permissionSpecificChecker = {};
 
 XPCOMUtils.defineLazyServiceGetter(this,
                                    "TelephonyService",
@@ -413,7 +413,10 @@ ContentPermissionPrompt.prototype = {
       type: type,
       permissions: permissions,
       id: requestId,
-      origin: principal.origin,
+      // This system app uses the origin from permission events to
+      // compare against the mozApp.origin of app windows, so we
+      // are not concerned with origin suffixes here (appId, etc).
+      origin: principal.originNoSuffix,
       isApp: isApp,
       remember: remember,
       isGranted: isGranted,
diff --git a/b2g/components/MailtoProtocolHandler.js b/b2g/components/MailtoProtocolHandler.js
index 60b1bbaaff..3f667ab53d 100644
--- a/b2g/components/MailtoProtocolHandler.js
+++ b/b2g/components/MailtoProtocolHandler.js
@@ -23,7 +23,7 @@ MailtoProtocolHandler.prototype = {
                  Ci.nsIProtocolHandler.URI_NOAUTH |
                  Ci.nsIProtocolHandler.URI_LOADABLE_BY_ANYONE |
                  Ci.nsIProtocolHandler.URI_DOES_NOT_RETURN_DATA,
-  allowPort: function() false,
+  allowPort: () => false,
 
   newURI: function Proto_newURI(aSpec, aOriginCharset) {
     let uri = Cc["@mozilla.org/network/simple-uri;1"].createInstance(Ci.nsIURI);
diff --git a/b2g/components/SimulatorScreen.js b/b2g/components/SimulatorScreen.js
index dea86fc795..18d8f5cc46 100644
--- a/b2g/components/SimulatorScreen.js
+++ b/b2g/components/SimulatorScreen.js
@@ -62,13 +62,13 @@ function hookScreen(window) {
   };
 
   Object.defineProperty(screen, 'width', {
-    get: function () GlobalSimulatorScreen.width
+    get: () => GlobalSimulatorScreen.width
   });
   Object.defineProperty(screen, 'height', {
-    get: function () GlobalSimulatorScreen.height
+    get: () => GlobalSimulatorScreen.height
   });
   Object.defineProperty(screen, 'mozOrientation', {
-    get: function () GlobalSimulatorScreen.mozOrientation
+    get: () => GlobalSimulatorScreen.mozOrientation
   });
 }
 
diff --git a/b2g/components/SmsProtocolHandler.js b/b2g/components/SmsProtocolHandler.js
index cfefcff039..339f8605fa 100644
--- a/b2g/components/SmsProtocolHandler.js
+++ b/b2g/components/SmsProtocolHandler.js
@@ -32,7 +32,7 @@ SmsProtocolHandler.prototype = {
                  Ci.nsIProtocolHandler.URI_NOAUTH |
                  Ci.nsIProtocolHandler.URI_LOADABLE_BY_ANYONE |
                  Ci.nsIProtocolHandler.URI_DOES_NOT_RETURN_DATA,
-  allowPort: function() false,
+  allowPort: () => false,
 
   newURI: function Proto_newURI(aSpec, aOriginCharset) {
     let uri = Cc["@mozilla.org/network/simple-uri;1"].createInstance(Ci.nsIURI);
diff --git a/b2g/components/TelProtocolHandler.js b/b2g/components/TelProtocolHandler.js
index 38e0f2785c..bbc0e02193 100644
--- a/b2g/components/TelProtocolHandler.js
+++ b/b2g/components/TelProtocolHandler.js
@@ -31,7 +31,7 @@ TelProtocolHandler.prototype = {
                  Ci.nsIProtocolHandler.URI_NOAUTH |
                  Ci.nsIProtocolHandler.URI_LOADABLE_BY_ANYONE |
                  Ci.nsIProtocolHandler.URI_DOES_NOT_RETURN_DATA,
-  allowPort: function() false,
+  allowPort: () => false,
 
   newURI: function Proto_newURI(aSpec, aOriginCharset) {
     let uri = Cc["@mozilla.org/network/simple-uri;1"].createInstance(Ci.nsIURI);
diff --git a/b2g/simulator/lib/simulator-process.js b/b2g/simulator/lib/simulator-process.js
index bf20cd0b52..43181f4921 100644
--- a/b2g/simulator/lib/simulator-process.js
+++ b/b2g/simulator/lib/simulator-process.js
@@ -21,10 +21,10 @@ const { EventEmitter } = Cu.import("resource://gre/modules/devtools/event-emitte
 // have trailing newlines.  And note that registerLogHandler actually registers
 // an error handler, despite its name.
 Subprocess.registerLogHandler(
-  function(s) console.error("subprocess: " + s.trim())
+  s => console.error("subprocess: " + s.trim())
 );
 Subprocess.registerDebugHandler(
-  function(s) console.debug("subprocess: " + s.trim())
+  s => console.debug("subprocess: " + s.trim())
 );
 
 function SimulatorProcess(options) {
@@ -38,7 +38,9 @@ function SimulatorProcess(options) {
 SimulatorProcess.prototype = {
 
   // check if b2g is running
-  get isRunning() !!this.process,
+  get isRunning() {
+    return !!this.process;
+  },
 
   /**
    * Start the process and connect the debugger client.
diff --git a/chrome/test/unit/test_no_remote_registration.js b/chrome/test/unit/test_no_remote_registration.js
index ac4f5745d7..0f55c7eca8 100644
--- a/chrome/test/unit/test_no_remote_registration.js
+++ b/chrome/test/unit/test_no_remote_registration.js
@@ -41,7 +41,7 @@ function ProtocolHandler(aScheme, aFlags)
 ProtocolHandler.prototype =
 {
   defaultPort: -1,
-  allowPort: function() false,
+  allowPort: () => false,
   newURI: function(aSpec, aCharset, aBaseURI)
   {
     let uri = Cc["@mozilla.org/network/standard-url;1"].
diff --git a/docshell/test/chrome/bug293235_window.xul b/docshell/test/chrome/bug293235_window.xul
index 94aee8bbb2..b5b359d48c 100644
--- a/docshell/test/chrome/bug293235_window.xul
+++ b/docshell/test/chrome/bug293235_window.xul
@@ -64,7 +64,9 @@
         },
       };
       os.addObserver(observer, URI_VISITED_RESOLUTION_TOPIC, false);
-      function notified() observer.notified;
+      function notified() {
+        return observer.notified;
+      }
 
       // Load a test page containing a link that should be initially
       // blue, per the :link style.
diff --git a/dom/animation/AnimationPerformanceWarning.cpp b/dom/animation/AnimationPerformanceWarning.cpp
index 21b91e3525..207bf05c54 100644
--- a/dom/animation/AnimationPerformanceWarning.cpp
+++ b/dom/animation/AnimationPerformanceWarning.cpp
@@ -52,15 +52,15 @@ AnimationPerformanceWarning::ToLocalizedString(
     case Type::TransformSVG:
       key = "AnimationWarningTransformSVG";
       break;
+    case Type::TransformWithGeometricProperties:
+      key = "AnimationWarningTransformWithGeometricProperties";
+      break;
     case Type::TransformFrameInactive:
       key = "AnimationWarningTransformFrameInactive";
       break;
     case Type::OpacityFrameInactive:
       key = "AnimationWarningOpacityFrameInactive";
       break;
-    case Type::WithGeometricProperties:
-      key = "AnimationWarningWithGeometricProperties";
-      break;
   }
 
   nsresult rv =
diff --git a/dom/animation/AnimationPerformanceWarning.h b/dom/animation/AnimationPerformanceWarning.h
index 11481fe437..4eb25bad2e 100644
--- a/dom/animation/AnimationPerformanceWarning.h
+++ b/dom/animation/AnimationPerformanceWarning.h
@@ -21,9 +21,9 @@ struct AnimationPerformanceWarning
     TransformBackfaceVisibilityHidden,
     TransformPreserve3D,
     TransformSVG,
+    TransformWithGeometricProperties,
     TransformFrameInactive,
     OpacityFrameInactive,
-    WithGeometricProperties
   };
 
   explicit AnimationPerformanceWarning(Type aType)
diff --git a/dom/animation/AnimationUtils.cpp b/dom/animation/AnimationUtils.cpp
index 1331203521..bab8bfa1f6 100644
--- a/dom/animation/AnimationUtils.cpp
+++ b/dom/animation/AnimationUtils.cpp
@@ -10,9 +10,12 @@
 #include "nsDebug.h"
 #include "nsIAtom.h"
 #include "nsIContent.h"
+#include "nsIDocument.h"
+#include "nsGlobalWindow.h"
 #include "nsString.h"
+#include "mozilla/Attributes.h"
 #include "mozilla/ComputedTimingFunction.h" // ComputedTimingFunction
-#include "mozilla/dom/Element.h" // For dom::Element
+#include "xpcpublic.h" // For xpc::NativeGlobal
 
 namespace mozilla {
 
@@ -37,22 +40,18 @@ AnimationUtils::LogAsyncAnimationFailure(nsCString& aMessage,
 }
 
 /* static */ Maybe<ComputedTimingFunction>
-AnimationUtils::ParseEasing(const dom::Element* aTarget,
-                            const nsAString& aEasing)
+AnimationUtils::ParseEasing(const nsAString& aEasing,
+                            nsIDocument* aDocument)
 {
-  if (!aTarget) {
-    return Nothing();
-  }
-
-  nsIDocument* doc = aTarget->OwnerDoc();
+  MOZ_ASSERT(aDocument);
 
   nsCSSValue value;
   nsCSSParser parser;
   parser.ParseLonghandProperty(eCSSProperty_animation_timing_function,
                                aEasing,
-                               doc->GetDocumentURI(),
-                               doc->GetDocumentURI(),
-                               doc->NodePrincipal(),
+                               aDocument->GetDocumentURI(),
+                               aDocument->GetDocumentURI(),
+                               aDocument->NodePrincipal(),
                                value);
 
   switch (value.GetUnit()) {
@@ -69,7 +68,7 @@ AnimationUtils::ParseEasing(const dom::Element* aTarget,
               NS_STYLE_TRANSITION_TIMING_FUNCTION_LINEAR) {
             return Nothing();
           }
-          // Fall through
+          MOZ_FALLTHROUGH;
         case eCSSUnit_Cubic_Bezier:
         case eCSSUnit_Steps: {
           nsTimingFunction timingFunction;
@@ -98,4 +97,14 @@ AnimationUtils::ParseEasing(const dom::Element* aTarget,
   return Nothing();
 }
 
+/* static */ nsIDocument*
+AnimationUtils::GetCurrentRealmDocument(JSContext* aCx)
+{
+  nsGlobalWindow* win = xpc::CurrentWindowOrNull(aCx);
+  if (!win) {
+    return nullptr;
+  }
+  return win->GetDoc();
+}
+
 } // namespace mozilla
diff --git a/dom/animation/AnimationUtils.h b/dom/animation/AnimationUtils.h
index c048aaa029..afe8e20a2a 100644
--- a/dom/animation/AnimationUtils.h
+++ b/dom/animation/AnimationUtils.h
@@ -12,20 +12,18 @@
 #include "nsStringFwd.h"
 
 class nsIContent;
+class nsIDocument;
+struct JSContext;
 
 namespace mozilla {
 
 class ComputedTimingFunction;
 
-namespace dom {
-class Element;
-}
-
 class AnimationUtils
 {
 public:
   static dom::Nullable<double>
-    TimeDurationToDouble(const dom::Nullable<TimeDuration>& aTime)
+  TimeDurationToDouble(const dom::Nullable<TimeDuration>& aTime)
   {
     dom::Nullable<double> result;
 
@@ -37,7 +35,7 @@ public:
   }
 
   static dom::Nullable<TimeDuration>
-    DoubleToTimeDuration(const dom::Nullable<double>& aTime)
+  DoubleToTimeDuration(const dom::Nullable<double>& aTime)
   {
     dom::Nullable<TimeDuration> result;
 
@@ -57,7 +55,13 @@ public:
    * be returned.
    */
   static Maybe<ComputedTimingFunction>
-    ParseEasing(const dom::Element* aTarget, const nsAString& aEasing);
+  ParseEasing(const nsAString& aEasing, nsIDocument* aDocument);
+
+  /**
+   * Get the document from the JS context to use when parsing CSS properties.
+   */
+  static nsIDocument*
+  GetCurrentRealmDocument(JSContext* aCx);
 };
 
 } // namespace mozilla
diff --git a/dom/animation/EffectCompositor.cpp b/dom/animation/EffectCompositor.cpp
index 4c2c80e7ce..d686ca3cba 100644
--- a/dom/animation/EffectCompositor.cpp
+++ b/dom/animation/EffectCompositor.cpp
@@ -19,7 +19,6 @@
 #include "nsComputedDOMStyle.h" // nsComputedDOMStyle::GetPresShellForContent
 #include "nsCSSPropertySet.h"
 #include "nsCSSProps.h"
-#include "nsCSSPseudoElements.h"
 #include "nsIPresShell.h"
 #include "nsLayoutUtils.h"
 #include "nsRuleNode.h" // For nsRuleNode::ComputePropertiesOverridingAnimation
@@ -83,11 +82,11 @@ FindAnimationsForCompositor(const nsIFrame* aFrame,
   // Those cases are probably not important but just to be safe, let's make
   // sure the cascade is up to date since if it *is* up to date, this is
   // basically a no-op.
-  Maybe<Pair<dom::Element*, CSSPseudoElementType>> pseudoElement =
+  Maybe<NonOwningAnimationTarget> pseudoElement =
     EffectCompositor::GetAnimationElementAndPseudoForFrame(aFrame);
   if (pseudoElement) {
-    EffectCompositor::MaybeUpdateCascadeResults(pseudoElement->first(),
-                                                pseudoElement->second(),
+    EffectCompositor::MaybeUpdateCascadeResults(pseudoElement->mElement,
+                                                pseudoElement->mPseudoType,
                                                 aFrame->StyleContext());
   }
 
@@ -111,13 +110,15 @@ FindAnimationsForCompositor(const nsIFrame* aFrame,
     }
 
     AnimationPerformanceWarning::Type warningType;
-    if (effect->ShouldBlockCompositorAnimations(aFrame,
-                                                warningType)) {
+    if (aProperty == eCSSProperty_transform &&
+        effect->ShouldBlockAsyncTransformAnimations(aFrame,
+                                                    warningType)) {
       if (aMatches) {
         aMatches->Clear();
       }
-      effect->SetPerformanceWarning(
-        aProperty, AnimationPerformanceWarning(warningType));
+      EffectCompositor::SetPerformanceWarning(
+        aFrame, aProperty,
+        AnimationPerformanceWarning(warningType));
       return false;
     }
 
@@ -148,7 +149,7 @@ EffectCompositor::RequestRestyle(dom::Element* aElement,
   }
 
   auto& elementsToRestyle = mElementsToRestyle[aCascadeLevel];
-  PseudoElementHashKey key = { aElement, aPseudoType };
+  PseudoElementHashEntry::KeyType key = { aElement, aPseudoType };
 
   if (aRestyleType == RestyleType::Throttled) {
     if (!elementsToRestyle.Contains(key)) {
@@ -230,7 +231,7 @@ EffectCompositor::MaybeUpdateAnimationRule(dom::Element* aElement,
   MaybeUpdateCascadeResults(aElement, aPseudoType);
 
   auto& elementsToRestyle = mElementsToRestyle[aCascadeLevel];
-  PseudoElementHashKey key = { aElement, aPseudoType };
+  PseudoElementHashEntry::KeyType key = { aElement, aPseudoType };
 
   if (!mPresContext || !elementsToRestyle.Contains(key)) {
     return;
@@ -276,7 +277,7 @@ EffectCompositor::GetAnimationRule(dom::Element* aElement,
 #ifdef DEBUG
   {
     auto& elementsToRestyle = mElementsToRestyle[aCascadeLevel];
-    PseudoElementHashKey key = { aElement, aPseudoType };
+    PseudoElementHashEntry::KeyType key = { aElement, aPseudoType };
     MOZ_ASSERT(!elementsToRestyle.Contains(key),
                "Element should no longer require a restyle after its "
                "animation rule has been updated");
@@ -362,7 +363,8 @@ EffectCompositor::AddStyleUpdatesTo(RestyleTracker& aTracker)
     // it will only mutate the bool value associated with each element in the
     // set but even doing that will cause assertions in PLDHashTable to fail
     // if we are iterating over the hashtable at the same time.
-    nsTArray<PseudoElementHashKey> elementsToRestyle(elementSet.Count());
+    nsTArray<PseudoElementHashEntry::KeyType> elementsToRestyle(
+      elementSet.Count());
     for (auto iter = elementSet.Iter(); !iter.Done(); iter.Next()) {
       elementsToRestyle.AppendElement(iter.Key());
     }
@@ -495,11 +497,11 @@ EffectCompositor::UpdateCascadeResults(Element* aElement,
   UpdateCascadeResults(*effects, aElement, aPseudoType, aStyleContext);
 }
 
-/* static */ Maybe<Pair<Element*, CSSPseudoElementType>>
+/* static */ Maybe<NonOwningAnimationTarget>
 EffectCompositor::GetAnimationElementAndPseudoForFrame(const nsIFrame* aFrame)
 {
   // Always return the same object to benefit from return-value optimization.
-  Maybe<Pair<Element*, CSSPseudoElementType>> result;
+  Maybe<NonOwningAnimationTarget> result;
 
   nsIContent* content = aFrame->GetContent();
   if (!content) {
@@ -536,7 +538,7 @@ EffectCompositor::GetAnimationElementAndPseudoForFrame(const nsIFrame* aFrame)
     return result;
   }
 
-  result = Some(MakePair(content->AsElement(), pseudoType));
+  result.emplace(content->AsElement(), pseudoType);
 
   return result;
 }
diff --git a/dom/animation/EffectCompositor.h b/dom/animation/EffectCompositor.h
index fbcbd1bc25..b1cdbfbfc1 100644
--- a/dom/animation/EffectCompositor.h
+++ b/dom/animation/EffectCompositor.h
@@ -10,7 +10,7 @@
 #include "mozilla/EnumeratedArray.h"
 #include "mozilla/Maybe.h"
 #include "mozilla/OwningNonNull.h"
-#include "mozilla/Pair.h"
+#include "mozilla/NonOwningAnimationTarget.h"
 #include "mozilla/PseudoElementHashEntry.h"
 #include "mozilla/RefPtr.h"
 #include "nsCSSProperty.h"
@@ -29,7 +29,6 @@ namespace mozilla {
 
 class EffectSet;
 class RestyleTracker;
-enum class CSSPseudoElementType : uint8_t;
 struct AnimationPerformanceWarning;
 
 namespace dom {
@@ -185,7 +184,7 @@ public:
   // Returns an empty result when a suitable element cannot be found including
   // when the frame represents a pseudo-element on which we do not support
   // animations.
-  static Maybe<Pair<dom::Element*, CSSPseudoElementType>>
+  static Maybe<NonOwningAnimationTarget>
   GetAnimationElementAndPseudoForFrame(const nsIFrame* aFrame);
 
   // Associates a performance warning with effects on |aFrame| that animates
diff --git a/dom/animation/KeyframeEffect.cpp b/dom/animation/KeyframeEffect.cpp
index 5c0c9a2f51..663e0c143e 100644
--- a/dom/animation/KeyframeEffect.cpp
+++ b/dom/animation/KeyframeEffect.cpp
@@ -6,6 +6,7 @@
 
 #include "mozilla/dom/KeyframeEffect.h"
 
+#include "mozilla/dom/AnimatableBinding.h"
 #include "mozilla/dom/KeyframeEffectBinding.h"
 #include "mozilla/dom/PropertyIndexedKeyframesBinding.h"
 #include "mozilla/AnimationUtils.h"
@@ -572,15 +573,15 @@ KeyframeEffectReadOnly::ComposeStyle(RefPtr<AnimValuesStyleRule>& aStyleRule,
     // FIXME: Maybe cache the current segment?
     const AnimationPropertySegment *segment = prop.mSegments.Elements(),
                                 *segmentEnd = segment + prop.mSegments.Length();
-    while (segment->mToKey < computedTiming.mProgress.Value()) {
-      MOZ_ASSERT(segment->mFromKey < segment->mToKey, "incorrect keys");
+    while (segment->mToKey <= computedTiming.mProgress.Value()) {
+      MOZ_ASSERT(segment->mFromKey <= segment->mToKey, "incorrect keys");
       if ((segment+1) == segmentEnd) {
         break;
       }
       ++segment;
       MOZ_ASSERT(segment->mFromKey == (segment-1)->mToKey, "incorrect keys");
     }
-    MOZ_ASSERT(segment->mFromKey < segment->mToKey, "incorrect keys");
+    MOZ_ASSERT(segment->mFromKey <= segment->mToKey, "incorrect keys");
     MOZ_ASSERT(segment >= prop.mSegments.Elements() &&
                size_t(segment - prop.mSegments.Elements()) <
                  prop.mSegments.Length(),
@@ -591,6 +592,18 @@ KeyframeEffectReadOnly::ComposeStyle(RefPtr<AnimValuesStyleRule>& aStyleRule,
       aStyleRule = new AnimValuesStyleRule();
     }
 
+    StyleAnimationValue* val = aStyleRule->AddEmptyValue(prop.mProperty);
+
+    // Special handling for zero-length segments
+    if (segment->mToKey == segment->mFromKey) {
+      if (computedTiming.mProgress.Value() < 0) {
+        *val = segment->mFromValue;
+      } else {
+        *val = segment->mToValue;
+      }
+      continue;
+    }
+
     double positionInSegment =
       (computedTiming.mProgress.Value() - segment->mFromKey) /
       (segment->mToKey - segment->mFromKey);
@@ -598,8 +611,6 @@ KeyframeEffectReadOnly::ComposeStyle(RefPtr<AnimValuesStyleRule>& aStyleRule,
       ComputedTimingFunction::GetPortion(segment->mTimingFunction,
                                          positionInSegment);
 
-    StyleAnimationValue *val = aStyleRule->AddEmptyValue(prop.mProperty);
-
 #ifdef DEBUG
     bool result =
 #endif
@@ -652,14 +663,27 @@ KeyframeEffectReadOnly::~KeyframeEffectReadOnly()
 {
 }
 
-template <class KeyframeEffectType>
+template <class KeyframeEffectType, class OptionsType>
 /* static */ already_AddRefed<KeyframeEffectType>
-KeyframeEffectReadOnly::ConstructKeyframeEffect(const GlobalObject& aGlobal,
-                                                const Nullable<ElementOrCSSPseudoElement>& aTarget,
-                                                JS::Handle<JSObject*> aFrames,
-                                                const TimingParams& aTiming,
-                                                ErrorResult& aRv)
+KeyframeEffectReadOnly::ConstructKeyframeEffect(
+    const GlobalObject& aGlobal,
+    const Nullable<ElementOrCSSPseudoElement>& aTarget,
+    JS::Handle<JSObject*> aFrames,
+    const OptionsType& aOptions,
+    ErrorResult& aRv)
 {
+  nsIDocument* doc = AnimationUtils::GetCurrentRealmDocument(aGlobal.Context());
+  if (!doc) {
+    aRv.Throw(NS_ERROR_FAILURE);
+    return nullptr;
+  }
+
+  TimingParams timingParams =
+    TimingParams::FromOptionsUnion(aOptions, doc, aRv);
+  if (aRv.Failed()) {
+    return nullptr;
+  }
+
   if (aTarget.IsNull()) {
     // We don't support null targets yet.
     aRv.Throw(NS_ERROR_DOM_ANIM_NO_TARGET_ERR);
@@ -694,29 +718,11 @@ KeyframeEffectReadOnly::ConstructKeyframeEffect(const GlobalObject& aGlobal,
 
   RefPtr<KeyframeEffectType> effect =
     new KeyframeEffectType(targetElement->OwnerDoc(), targetElement,
-                           pseudoType, aTiming);
+                           pseudoType, timingParams);
   effect->mProperties = Move(animationProperties);
   return effect.forget();
 }
 
-// Explicit instantiations to avoid linker errors.
-
-template
-already_AddRefed<KeyframeEffectReadOnly>
-KeyframeEffectReadOnly::ConstructKeyframeEffect<>(const GlobalObject& aGlobal,
-                                                  const Nullable<ElementOrCSSPseudoElement>& aTarget,
-                                                  JS::Handle<JSObject*> aFrames,
-                                                  const TimingParams& aTiming,
-                                                  ErrorResult& aRv);
-
-template
-already_AddRefed<KeyframeEffect>
-KeyframeEffectReadOnly::ConstructKeyframeEffect<>(const GlobalObject& aGlobal,
-                                                  const Nullable<ElementOrCSSPseudoElement>& aTarget,
-                                                  JS::Handle<JSObject*> aFrames,
-                                                  const TimingParams& aTiming,
-                                                  ErrorResult& aRv);
-
 void
 KeyframeEffectReadOnly::ResetIsRunningOnCompositor()
 {
@@ -1287,10 +1293,9 @@ GenerateValueEntries(Element* aTarget,
 
   for (OffsetIndexedKeyframe& keyframe : aKeyframes) {
     float offset = float(keyframe.mKeyframeDict.mOffset.Value());
-    // ParseEasing uses element's owner doc, so if it is a pseudo element,
-    // we use its parent element's owner doc.
     Maybe<ComputedTimingFunction> easing =
-      AnimationUtils::ParseEasing(aTarget, keyframe.mKeyframeDict.mEasing);
+      AnimationUtils::ParseEasing(keyframe.mKeyframeDict.mEasing,
+                                  aTarget->OwnerDoc());
     // We ignore keyframe.mKeyframeDict.mComposite since we don't support
     // composite modes on keyframes yet.
 
@@ -1554,10 +1559,8 @@ BuildAnimationPropertyListFromPropertyIndexedKeyframes(
     return;
   }
 
-  // ParseEasing uses element's owner doc, so if it is a pseudo element,
-  // we use its parent element's owner doc.
   Maybe<ComputedTimingFunction> easing =
-    AnimationUtils::ParseEasing(aTarget, keyframes.mEasing);
+    AnimationUtils::ParseEasing(keyframes.mEasing, aTarget->OwnerDoc());
 
   // We ignore easing.mComposite since we don't support composite modes on
   // keyframes yet.
@@ -1757,6 +1760,19 @@ KeyframeEffectReadOnly::BuildAnimationPropertyList(
   }
 }
 
+/* static */ already_AddRefed<KeyframeEffectReadOnly>
+KeyframeEffectReadOnly::Constructor(
+    const GlobalObject& aGlobal,
+    const Nullable<ElementOrCSSPseudoElement>& aTarget,
+    JS::Handle<JSObject*> aFrames,
+    const UnrestrictedDoubleOrKeyframeEffectOptions& aOptions,
+    ErrorResult& aRv)
+{
+  return ConstructKeyframeEffect<KeyframeEffectReadOnly>(aGlobal, aTarget,
+                                                         aFrames, aOptions,
+                                                         aRv);
+}
+
 void
 KeyframeEffectReadOnly::GetTarget(
     Nullable<OwningElementOrCSSPseudoElement>& aRv) const
@@ -1783,6 +1799,93 @@ KeyframeEffectReadOnly::GetTarget(
   }
 }
 
+static void
+CreatePropertyValue(nsCSSProperty aProperty,
+                    float aOffset,
+                    const Maybe<ComputedTimingFunction>& aTimingFunction,
+                    const StyleAnimationValue& aValue,
+                    AnimationPropertyValueDetails& aResult)
+{
+  aResult.mOffset = aOffset;
+
+  nsString stringValue;
+  StyleAnimationValue::UncomputeValue(aProperty, aValue, stringValue);
+  aResult.mValue = stringValue;
+
+  if (aTimingFunction) {
+    aResult.mEasing.Construct();
+    aTimingFunction->AppendToString(aResult.mEasing.Value());
+  } else {
+    aResult.mEasing.Construct(NS_LITERAL_STRING("linear"));
+  }
+
+  aResult.mComposite = CompositeOperation::Replace;
+}
+
+void
+KeyframeEffectReadOnly::GetProperties(
+    nsTArray<AnimationPropertyDetails>& aProperties,
+    ErrorResult& aRv) const
+{
+  for (const AnimationProperty& property : mProperties) {
+    AnimationPropertyDetails propertyDetails;
+    propertyDetails.mProperty =
+      NS_ConvertASCIItoUTF16(nsCSSProps::GetStringValue(property.mProperty));
+    propertyDetails.mRunningOnCompositor = property.mIsRunningOnCompositor;
+
+    nsXPIDLString localizedString;
+    if (property.mPerformanceWarning &&
+        property.mPerformanceWarning->ToLocalizedString(localizedString)) {
+      propertyDetails.mWarning.Construct(localizedString);
+    }
+
+    if (!propertyDetails.mValues.SetCapacity(property.mSegments.Length(),
+                                             mozilla::fallible)) {
+      aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
+      return;
+    }
+
+    for (size_t segmentIdx = 0, segmentLen = property.mSegments.Length();
+         segmentIdx < segmentLen;
+         segmentIdx++)
+    {
+      const AnimationPropertySegment& segment = property.mSegments[segmentIdx];
+
+      binding_detail::FastAnimationPropertyValueDetails fromValue;
+      CreatePropertyValue(property.mProperty, segment.mFromKey,
+                          segment.mTimingFunction, segment.mFromValue,
+                          fromValue);
+      // We don't apply timing functions for zero-length segments, so
+      // don't return one here.
+      if (segment.mFromKey == segment.mToKey) {
+        fromValue.mEasing.Reset();
+      }
+      // The following won't fail since we have already allocated the capacity
+      // above.
+      propertyDetails.mValues.AppendElement(fromValue, mozilla::fallible);
+
+      // Normally we can ignore the to-value for this segment since it is
+      // identical to the from-value from the next segment. However, we need
+      // to add it if either:
+      // a) this is the last segment, or
+      // b) the next segment's from-value differs.
+      if (segmentIdx == segmentLen - 1 ||
+          property.mSegments[segmentIdx + 1].mFromValue != segment.mToValue) {
+        binding_detail::FastAnimationPropertyValueDetails toValue;
+        CreatePropertyValue(property.mProperty, segment.mToKey,
+                            Nothing(), segment.mToValue, toValue);
+        // It doesn't really make sense to have a timing function on the
+        // last property value or before a sudden jump so we just drop the
+        // easing property altogether.
+        toValue.mEasing.Reset();
+        propertyDetails.mValues.AppendElement(toValue, mozilla::fallible);
+      }
+    }
+
+    aProperties.AppendElement(propertyDetails);
+  }
+}
+
 void
 KeyframeEffectReadOnly::GetFrames(JSContext*& aCx,
                                   nsTArray<JSObject*>& aResult,
@@ -1881,32 +1984,6 @@ KeyframeEffectReadOnly::GetFrames(JSContext*& aCx,
   }
 }
 
-
-void
-KeyframeEffectReadOnly::GetPropertyState(
-    nsTArray<AnimationPropertyState>& aStates) const
-{
-  for (const AnimationProperty& property : mProperties) {
-    // Bug 1252730: We should also expose this winsInCascade as well.
-    if (!property.mWinsInCascade) {
-      continue;
-    }
-
-    AnimationPropertyState state;
-    state.mProperty.Construct(
-      NS_ConvertASCIItoUTF16(nsCSSProps::GetStringValue(property.mProperty)));
-    state.mRunningOnCompositor.Construct(property.mIsRunningOnCompositor);
-
-    nsXPIDLString localizedString;
-    if (property.mPerformanceWarning &&
-        property.mPerformanceWarning->ToLocalizedString(localizedString)) {
-      state.mWarning.Construct(localizedString);
-    }
-
-    aStates.AppendElement(state);
-  }
-}
-
 /* static */ const TimeDuration
 KeyframeEffectReadOnly::OverflowRegionRefreshInterval()
 {
@@ -2135,7 +2212,7 @@ KeyframeEffectReadOnly::CanAnimateTransformOnCompositor(
 }
 
 bool
-KeyframeEffectReadOnly::ShouldBlockCompositorAnimations(
+KeyframeEffectReadOnly::ShouldBlockAsyncTransformAnimations(
   const nsIFrame* aFrame,
   AnimationPerformanceWarning::Type& aPerformanceWarning) const
 {
@@ -2155,7 +2232,7 @@ KeyframeEffectReadOnly::ShouldBlockCompositorAnimations(
     // Check for geometric properties
     if (IsGeometricProperty(property.mProperty)) {
       aPerformanceWarning =
-        AnimationPerformanceWarning::Type::WithGeometricProperties;
+        AnimationPerformanceWarning::Type::TransformWithGeometricProperties;
       return true;
     }
 
@@ -2215,6 +2292,30 @@ KeyframeEffect::WrapObject(JSContext* aCx,
   return KeyframeEffectBinding::Wrap(aCx, this, aGivenProto);
 }
 
+/* static */ already_AddRefed<KeyframeEffect>
+KeyframeEffect::Constructor(
+    const GlobalObject& aGlobal,
+    const Nullable<ElementOrCSSPseudoElement>& aTarget,
+    JS::Handle<JSObject*> aFrames,
+    const UnrestrictedDoubleOrKeyframeEffectOptions& aOptions,
+    ErrorResult& aRv)
+{
+  return ConstructKeyframeEffect<KeyframeEffect>(aGlobal, aTarget, aFrames,
+                                                 aOptions, aRv);
+}
+
+/* static */ already_AddRefed<KeyframeEffect>
+KeyframeEffect::Constructor(
+    const GlobalObject& aGlobal,
+    const Nullable<ElementOrCSSPseudoElement>& aTarget,
+    JS::Handle<JSObject*> aFrames,
+    const UnrestrictedDoubleOrKeyframeAnimationOptions& aOptions,
+    ErrorResult& aRv)
+{
+  return ConstructKeyframeEffect<KeyframeEffect>(aGlobal, aTarget, aFrames,
+                                                 aOptions, aRv);
+}
+
 void KeyframeEffect::NotifySpecifiedTimingUpdated()
 {
   nsIDocument* doc = nullptr;
diff --git a/dom/animation/KeyframeEffect.h b/dom/animation/KeyframeEffect.h
index 7f44bf1c18..8071a9fc8e 100644
--- a/dom/animation/KeyframeEffect.h
+++ b/dom/animation/KeyframeEffect.h
@@ -42,10 +42,11 @@ enum class CSSPseudoElementType : uint8_t;
 namespace dom {
 class ElementOrCSSPseudoElement;
 class OwningElementOrCSSPseudoElement;
+class UnrestrictedDoubleOrKeyframeAnimationOptions;
 class UnrestrictedDoubleOrKeyframeEffectOptions;
 enum class IterationCompositeOperation : uint32_t;
 enum class CompositeOperation : uint32_t;
-struct AnimationPropertyState;
+struct AnimationPropertyDetails;
 }
 
 /**
@@ -202,21 +203,14 @@ public:
               const Nullable<ElementOrCSSPseudoElement>& aTarget,
               JS::Handle<JSObject*> aFrames,
               const UnrestrictedDoubleOrKeyframeEffectOptions& aOptions,
-              ErrorResult& aRv)
-  {
-    TimingParams timingParams =
-      TimingParams::FromOptionsUnion(aOptions, aTarget, aRv);
-    if (aRv.Failed()) {
-      return nullptr;
-    }
-    return ConstructKeyframeEffect<KeyframeEffectReadOnly>(
-             aGlobal, aTarget, aFrames, timingParams, aRv);
-  }
+              ErrorResult& aRv);
 
   void GetTarget(Nullable<OwningElementOrCSSPseudoElement>& aRv) const;
   void GetFrames(JSContext*& aCx,
                  nsTArray<JSObject*>& aResult,
                  ErrorResult& aRv);
+  void GetProperties(nsTArray<AnimationPropertyDetails>& aProperties,
+                     ErrorResult& aRv) const;
 
   // Temporary workaround to return both the target element and pseudo-type
   // until we implement PseudoElement (bug 1174575).
@@ -312,26 +306,16 @@ public:
   bool IsRunningOnCompositor() const;
   void SetIsRunningOnCompositor(nsCSSProperty aProperty, bool aIsRunning);
 
-  void GetPropertyState(nsTArray<AnimationPropertyState>& aStates) const;
-
-  // Returns true if this effect, applied to |aFrame|, contains
-  // properties that mean we shouldn't run *any* compositor animations on this
-  // element.
+  // Returns true if this effect, applied to |aFrame|, contains properties
+  // that mean we shouldn't run transform compositor animations on this element.
   //
   // For example, if we have an animation of geometric properties like 'left'
-  // and 'top' on an element, we force all 'transform' and 'opacity' animations
-  // running at the same time on the same element to run on the main thread.
+  // and 'top' on an element, we force all 'transform' animations running at
+  // the same time on the same element to run on the main thread.
   //
-  // Similarly, some transform animations cannot be run on the compositor and
-  // when that is the case we simply disable all compositor animations
-  // on the same element.
-  //
-  // Bug 1218620 - It seems like we don't need to be this restrictive. Wouldn't
-  // it be ok to do 'opacity' animations on the compositor in either case?
-  //
-  // When returning true, |aOutPerformanceWarning| stores the reason why
-  // we shouldn't run the compositor animations.
-  bool ShouldBlockCompositorAnimations(
+  // When returning true, |aPerformanceWarning| stores the reason why
+  // we shouldn't run the transform animations.
+  bool ShouldBlockAsyncTransformAnimations(
     const nsIFrame* aFrame,
     AnimationPerformanceWarning::Type& aPerformanceWarning) const;
 
@@ -354,12 +338,12 @@ protected:
 
   virtual ~KeyframeEffectReadOnly();
 
-  template<typename KeyframeEffectType>
+  template<class KeyframeEffectType, class OptionsType>
   static already_AddRefed<KeyframeEffectType>
   ConstructKeyframeEffect(const GlobalObject& aGlobal,
                           const Nullable<ElementOrCSSPseudoElement>& aTarget,
                           JS::Handle<JSObject*> aFrames,
-                          const TimingParams& aTiming,
+                          const OptionsType& aOptions,
                           ErrorResult& aRv);
 
   void ResetIsRunningOnCompositor();
@@ -433,29 +417,17 @@ public:
               const Nullable<ElementOrCSSPseudoElement>& aTarget,
               JS::Handle<JSObject*> aFrames,
               const UnrestrictedDoubleOrKeyframeEffectOptions& aOptions,
-              ErrorResult& aRv)
-  {
-    TimingParams timingParams =
-      TimingParams::FromOptionsUnion(aOptions, aTarget, aRv);
-    if (aRv.Failed()) {
-      return nullptr;
-    }
-    return ConstructKeyframeEffect<KeyframeEffect>(
-      aGlobal, aTarget, aFrames, timingParams, aRv);
-  }
+              ErrorResult& aRv);
 
-  // More generalized version for Animatable.animate.
+  // Variant of Constructor that accepts a KeyframeAnimationOptions object
+  // for use with for Animatable.animate.
   // Not exposed to content.
   static already_AddRefed<KeyframeEffect>
-  inline Constructor(const GlobalObject& aGlobal,
-                     const Nullable<ElementOrCSSPseudoElement>& aTarget,
-                     JS::Handle<JSObject*> aFrames,
-                     const TimingParams& aTiming,
-                     ErrorResult& aRv)
-  {
-    return ConstructKeyframeEffect<KeyframeEffect>(aGlobal, aTarget, aFrames,
-                                                   aTiming, aRv);
-  }
+  Constructor(const GlobalObject& aGlobal,
+              const Nullable<ElementOrCSSPseudoElement>& aTarget,
+              JS::Handle<JSObject*> aFrames,
+              const UnrestrictedDoubleOrKeyframeAnimationOptions& aOptions,
+              ErrorResult& aRv);
 
   void NotifySpecifiedTimingUpdated();
 
diff --git a/dom/animation/NonOwningAnimationTarget.h b/dom/animation/NonOwningAnimationTarget.h
new file mode 100644
index 0000000000..b35e45505e
--- /dev/null
+++ b/dom/animation/NonOwningAnimationTarget.h
@@ -0,0 +1,32 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_NonOwningAnimationTarget_h
+#define mozilla_NonOwningAnimationTarget_h
+
+#include "mozilla/Attributes.h"   // For MOZ_NON_OWNING_REF
+#include "nsCSSPseudoElements.h"
+
+namespace mozilla {
+
+namespace dom {
+class Element;
+} // namespace dom
+
+struct NonOwningAnimationTarget
+{
+  NonOwningAnimationTarget(dom::Element* aElement, CSSPseudoElementType aType)
+    : mElement(aElement), mPseudoType(aType) { }
+
+  // mElement represents the parent element of a pseudo-element, not the
+  // generated content element.
+  dom::Element* MOZ_NON_OWNING_REF mElement = nullptr;
+  CSSPseudoElementType mPseudoType = CSSPseudoElementType::NotPseudo;
+};
+
+} // namespace mozilla
+
+#endif // mozilla_NonOwningAnimationTarget_h
diff --git a/dom/animation/PseudoElementHashEntry.h b/dom/animation/PseudoElementHashEntry.h
index b84f7c018d..12a20af17d 100644
--- a/dom/animation/PseudoElementHashEntry.h
+++ b/dom/animation/PseudoElementHashEntry.h
@@ -9,24 +9,17 @@
 
 #include "mozilla/dom/Element.h"
 #include "mozilla/HashFunctions.h"
+#include "mozilla/NonOwningAnimationTarget.h"
 #include "PLDHashTable.h"
 
 namespace mozilla {
 
-enum class CSSPseudoElementType : uint8_t;
-
-struct PseudoElementHashKey
-{
-  dom::Element* mElement;
-  CSSPseudoElementType mPseudoType;
-};
-
 // A hash entry that uses a RefPtr<dom::Element>, CSSPseudoElementType pair
 class PseudoElementHashEntry : public PLDHashEntryHdr
 {
 public:
-  typedef PseudoElementHashKey KeyType;
-  typedef const PseudoElementHashKey* KeyTypePointer;
+  typedef NonOwningAnimationTarget KeyType;
+  typedef const NonOwningAnimationTarget* KeyTypePointer;
 
   explicit PseudoElementHashEntry(KeyTypePointer aKey)
     : mElement(aKey->mElement)
@@ -35,7 +28,7 @@ public:
 
   ~PseudoElementHashEntry() = default;
 
-  KeyType GetKey() const { return {mElement, mPseudoType}; }
+  KeyType GetKey() const { return { mElement, mPseudoType }; }
   bool KeyEquals(KeyTypePointer aKey) const
   {
     return mElement == aKey->mElement &&
diff --git a/dom/animation/TimingParams.cpp b/dom/animation/TimingParams.cpp
index 9c797d04ef..0092bfeefc 100644
--- a/dom/animation/TimingParams.cpp
+++ b/dom/animation/TimingParams.cpp
@@ -6,6 +6,8 @@
 
 #include "mozilla/TimingParams.h"
 
+#include "nsIDocument.h"
+
 namespace mozilla {
 
 template <class OptionsType>
@@ -32,10 +34,9 @@ GetTimingProperties(
 
 template <class OptionsType>
 static TimingParams
-TimingParamsFromOptionsUnion(
-  const OptionsType& aOptions,
-  const Nullable<dom::ElementOrCSSPseudoElement>& aTarget,
-  ErrorResult& aRv)
+TimingParamsFromOptionsUnion(const OptionsType& aOptions,
+                             nsIDocument* aDocument,
+                             ErrorResult& aRv)
 {
   TimingParams result;
   if (aOptions.IsUnrestrictedDouble()) {
@@ -47,21 +48,6 @@ TimingParamsFromOptionsUnion(
       aRv.Throw(NS_ERROR_DOM_TYPE_ERR);
     }
   } else {
-    // If aTarget is a pseudo element, we pass its parent element because
-    // TimingParams only needs its owner doc to parse easing and both pseudo
-    // element and its parent element should have the same owner doc.
-    // Bug 1246320: Avoid passing the element for parsing the timing function
-    RefPtr<dom::Element> targetElement;
-    if (!aTarget.IsNull()) {
-      const dom::ElementOrCSSPseudoElement& target = aTarget.Value();
-      MOZ_ASSERT(target.IsElement() || target.IsCSSPseudoElement(),
-                 "Uninitialized target");
-      if (target.IsElement()) {
-        targetElement = &target.GetAsElement();
-      } else {
-        targetElement = target.GetAsCSSPseudoElement().ParentElement();
-      }
-    }
     const dom::AnimationEffectTimingProperties& timing =
       GetTimingProperties(aOptions);
 
@@ -82,8 +68,7 @@ TimingParamsFromOptionsUnion(
     result.mIterationStart = timing.mIterationStart;
     result.mDirection = timing.mDirection;
     result.mFill = timing.mFill;
-    result.mFunction =
-      AnimationUtils::ParseEasing(targetElement, timing.mEasing);
+    result.mFunction = AnimationUtils::ParseEasing(timing.mEasing, aDocument);
   }
   return result;
 }
@@ -91,19 +76,19 @@ TimingParamsFromOptionsUnion(
 /* static */ TimingParams
 TimingParams::FromOptionsUnion(
   const dom::UnrestrictedDoubleOrKeyframeEffectOptions& aOptions,
-  const Nullable<dom::ElementOrCSSPseudoElement>& aTarget,
+  nsIDocument* aDocument,
   ErrorResult& aRv)
 {
-  return TimingParamsFromOptionsUnion(aOptions, aTarget, aRv);
+  return TimingParamsFromOptionsUnion(aOptions, aDocument, aRv);
 }
 
 /* static */ TimingParams
 TimingParams::FromOptionsUnion(
   const dom::UnrestrictedDoubleOrKeyframeAnimationOptions& aOptions,
-  const Nullable<dom::ElementOrCSSPseudoElement>& aTarget,
+  nsIDocument* aDocument,
   ErrorResult& aRv)
 {
-  return TimingParamsFromOptionsUnion(aOptions, aTarget, aRv);
+  return TimingParamsFromOptionsUnion(aOptions, aDocument, aRv);
 }
 
 bool
diff --git a/dom/animation/TimingParams.h b/dom/animation/TimingParams.h
index 22cda11fe0..7c3a4320e6 100644
--- a/dom/animation/TimingParams.h
+++ b/dom/animation/TimingParams.h
@@ -17,17 +17,16 @@
 #ifdef None
 #undef None
 #endif
-#include "mozilla/dom/AnimationEffectReadOnlyBinding.h"  // for FillMode
-                                                         // and PlaybackDirection
+#include "mozilla/dom/AnimationEffectReadOnlyBinding.h" // for FillMode
+                                                        // and PlaybackDirection
+
+class nsIDocument;
 
 namespace mozilla {
 
 namespace dom {
-struct AnimationEffectTimingProperties;
-class Element;
 class UnrestrictedDoubleOrKeyframeEffectOptions;
 class UnrestrictedDoubleOrKeyframeAnimationOptions;
-class ElementOrCSSPseudoElement;
 }
 
 struct TimingParams
@@ -36,12 +35,10 @@ struct TimingParams
 
   static TimingParams FromOptionsUnion(
     const dom::UnrestrictedDoubleOrKeyframeEffectOptions& aOptions,
-    const Nullable<dom::ElementOrCSSPseudoElement>& aTarget,
-    ErrorResult& aRv);
+    nsIDocument* aDocument, ErrorResult& aRv);
   static TimingParams FromOptionsUnion(
     const dom::UnrestrictedDoubleOrKeyframeAnimationOptions& aOptions,
-    const Nullable<dom::ElementOrCSSPseudoElement>& aTarget,
-    ErrorResult& aRv);
+    nsIDocument* aDocument, ErrorResult& aRv);
 
   // Range-checks and validates an UnrestrictedDoubleOrString or
   // OwningUnrestrictedDoubleOrString object and converts to a
diff --git a/dom/animation/moz.build b/dom/animation/moz.build
index 1b1e7ee28a..8dcb1c1ad0 100644
--- a/dom/animation/moz.build
+++ b/dom/animation/moz.build
@@ -26,6 +26,7 @@ EXPORTS.mozilla += [
     'ComputedTimingFunction.h',
     'EffectCompositor.h',
     'EffectSet.h',
+    'NonOwningAnimationTarget.h',
     'PendingAnimationTracker.h',
     'PseudoElementHashEntry.h',
     'TimingParams.h',
diff --git a/dom/animation/test/chrome.ini b/dom/animation/test/chrome.ini
index ab725257ec..c63f67c09d 100644
--- a/dom/animation/test/chrome.ini
+++ b/dom/animation/test/chrome.ini
@@ -7,6 +7,7 @@ support-files =
 # file_animate_xrays.html needs to go in mochitest.ini since it is served
 # over HTTP
 [chrome/test_animation_observers.html]
+[chrome/test_animation_properties.html]
 [chrome/test_animation_property_state.html]
 [chrome/test_restyles.html]
 [chrome/test_running_on_compositor.html]
diff --git a/dom/animation/test/chrome/test_animation_properties.html b/dom/animation/test/chrome/test_animation_properties.html
new file mode 100644
index 0000000000..00e94f8340
--- /dev/null
+++ b/dom/animation/test/chrome/test_animation_properties.html
@@ -0,0 +1,503 @@
+<!doctype html>
+<head>
+<meta charset=utf-8>
+<title>Bug 1254419 - Test the values returned by
+       KeyframeEffectReadOnly.getProperties()</title>
+<script type="application/javascript" src="../testharness.js"></script>
+<script type="application/javascript" src="../testharnessreport.js"></script>
+<script type="application/javascript" src="../testcommon.js"></script>
+</head>
+<body>
+<a href="https://bugzilla.mozilla.org/show_bug.cgi?id=1254419"
+  target="_blank">Mozilla Bug 1254419</a>
+<div id="log"></div>
+<style>
+div {
+  font-size: 10px; /* For calculating em-based units */
+}
+</style>
+<script>
+'use strict';
+
+function assert_properties_equal(actual, expected) {
+  assert_equals(actual.length, expected.length);
+
+  var compareProperties = (a, b) =>
+    a.property == b.property ? 0 : (a.property < b.property ? -1 : 1);
+
+  var sortedActual   = actual.sort(compareProperties);
+  var sortedExpected = expected.sort(compareProperties);
+
+  // We want to serialize the values in the following form:
+  //
+  //  { offset: 0, easing: linear, composite: replace, value: 5px }, ...
+  //
+  // So that we can just compare strings and, in the failure case,
+  // easily see where the differences lie.
+  var serializeMember = value => {
+    return typeof value === 'undefined' ? '<not set>' : value;
+  }
+  var serializeValues = values =>
+    values.map(value =>
+      '{ ' +
+        [ 'offset', 'value', 'easing', 'composite' ].map(
+          member => `${member}: ${serializeMember(value[member])}`
+        ).join(', ') +
+      ' }')
+    .join(', ');
+
+  for (var i = 0; i < sortedActual.length; i++) {
+    assert_equals(sortedActual[i].property,
+                  sortedExpected[i].property,
+                  'CSS property name should match');
+    assert_equals(serializeValues(sortedActual[i].values),
+                  serializeValues(sortedExpected[i].values),
+                  `Values arrays do not match for `
+                  + `${sortedActual[i].property} property`);
+  }
+}
+
+// Shorthand for constructing a value object
+function value(offset, value, composite, easing) {
+  return { offset: offset, value: value, easing: easing, composite: composite };
+}
+
+var gTests = [
+
+  // ---------------------------------------------------------------------
+  //
+  // Tests for property-indexed specifications
+  //
+  // ---------------------------------------------------------------------
+
+  { desc:     'a one-property two-value property-indexed specification',
+    frames:   { left: ['10px', '20px'] },
+    expected: [ { property: 'left',
+                  values: [ value(0, '10px', 'replace', 'linear'),
+                            value(1, '20px', 'replace') ] } ]
+  },
+  { desc:     'a one-shorthand-property two-value property-indexed'
+              + ' specification',
+    frames:   { margin: ['10px', '10px 20px 30px 40px'] },
+    expected: [ { property: 'margin-top',
+                  values: [ value(0, '10px', 'replace', 'linear'),
+                            value(1, '10px', 'replace') ] },
+                { property: 'margin-right',
+                  values: [ value(0, '10px', 'replace', 'linear'),
+                            value(1, '20px', 'replace') ] },
+                { property: 'margin-bottom',
+                  values: [ value(0, '10px', 'replace', 'linear'),
+                            value(1, '30px', 'replace') ] },
+                { property: 'margin-left',
+                  values: [ value(0, '10px', 'replace', 'linear'),
+                            value(1, '40px', 'replace') ] } ]
+  },
+  { desc:     'a two-property (one shorthand and one of its longhand'
+              + ' components) two-value property-indexed specification',
+    frames:   { marginTop: ['50px', '60px'],
+                margin: ['10px', '10px 20px 30px 40px'] },
+    expected: [ { property: 'margin-top',
+                  values: [ value(0, '50px', 'replace', 'linear'),
+                            value(1, '60px', 'replace') ] },
+                { property: 'margin-right',
+                  values: [ value(0, '10px', 'replace', 'linear'),
+                            value(1, '20px', 'replace') ] },
+                { property: 'margin-bottom',
+                  values: [ value(0, '10px', 'replace', 'linear'),
+                            value(1, '30px', 'replace') ] },
+                { property: 'margin-left',
+                  values: [ value(0, '10px', 'replace', 'linear'),
+                            value(1, '40px', 'replace') ] } ]
+  },
+  { desc:     'a two-property property-indexed specification with different'
+              + ' numbers of values',
+    frames:   { left: ['10px', '20px', '30px'],
+                top: ['40px', '50px'] },
+    expected: [ { property: 'left',
+                  values: [ value(0, '10px', 'replace', 'linear'),
+                            value(0.5, '20px', 'replace', 'linear'),
+                            value(1, '30px', 'replace') ] },
+                { property: 'top',
+                  values: [ value(0, '40px', 'replace', 'linear'),
+                            value(1, '50px', 'replace') ] } ]
+  },
+  { desc:     'a property-indexed specification with an invalid value',
+    frames:   { left: ['10px', '20px', '30px', '40px', '50px'],
+                top:  ['15px', '25px', 'invalid', '45px', '55px'] },
+    expected: [ { property: 'left',
+                  values: [ value(0, '10px', 'replace', 'linear'),
+                            value(0.25, '20px', 'replace', 'linear'),
+                            value(0.5, '30px', 'replace', 'linear'),
+                            value(0.75, '40px', 'replace', 'linear'),
+                            value(1, '50px', 'replace') ] },
+                { property: 'top',
+                  values: [ value(0, '15px', 'replace', 'linear'),
+                            value(0.25, '25px', 'replace', 'linear'),
+                            value(0.75, '45px', 'replace', 'linear'),
+                            value(1, '55px', 'replace') ] } ]
+  },
+  { desc:     'a one-property two-value property-indexed specification that'
+              + ' needs to stringify its values',
+    frames:   { opacity: [0, 1] },
+    expected: [ { property: 'opacity',
+                  values: [ value(0, '0', 'replace', 'linear'),
+                            value(1, '1', 'replace') ] } ]
+  },
+  { desc:     'a property-indexed keyframe where a lesser shorthand precedes'
+              + ' a greater shorthand',
+    frames:   { borderLeft: [ '1px solid rgb(1, 2, 3)',
+                              '2px solid rgb(4, 5, 6)' ],
+                border:     [ '3px dotted rgb(7, 8, 9)',
+                              '4px dashed rgb(10, 11, 12)' ] },
+    expected: [ { property: 'border-bottom-color',
+                  values: [ value(0, 'rgb(7, 8, 9)', 'replace', 'linear'),
+                            value(1, 'rgb(10, 11, 12)', 'replace') ] },
+                { property: 'border-left-color',
+                  values: [ value(0, 'rgb(1, 2, 3)', 'replace', 'linear'),
+                            value(1, 'rgb(4, 5, 6)', 'replace') ] },
+                { property: 'border-right-color',
+                  values: [ value(0, 'rgb(7, 8, 9)', 'replace', 'linear'),
+                            value(1, 'rgb(10, 11, 12)', 'replace') ] },
+                { property: 'border-top-color',
+                  values: [ value(0, 'rgb(7, 8, 9)', 'replace', 'linear'),
+                            value(1, 'rgb(10, 11, 12)', 'replace') ] },
+                { property: 'border-bottom-width',
+                  values: [ value(0, '3px', 'replace', 'linear'),
+                            value(1, '4px', 'replace') ] },
+                { property: 'border-left-width',
+                  values: [ value(0, '1px', 'replace', 'linear'),
+                            value(1, '2px', 'replace') ] },
+                { property: 'border-right-width',
+                  values: [ value(0, '3px', 'replace', 'linear'),
+                            value(1, '4px', 'replace') ] },
+                { property: 'border-top-width',
+                  values: [ value(0, '3px', 'replace', 'linear'),
+                            value(1, '4px', 'replace') ] } ]
+  },
+  { desc:     'a property-indexed keyframe where a greater shorthand precedes'
+              + ' a lesser shorthand',
+    frames:   { border:     [ '3px dotted rgb(7, 8, 9)',
+                              '4px dashed rgb(10, 11, 12)' ],
+                borderLeft: [ '1px solid rgb(1, 2, 3)',
+                              '2px solid rgb(4, 5, 6)' ] },
+    expected: [ { property: 'border-bottom-color',
+                  values: [ value(0, 'rgb(7, 8, 9)', 'replace', 'linear'),
+                            value(1, 'rgb(10, 11, 12)', 'replace') ] },
+                { property: 'border-left-color',
+                  values: [ value(0, 'rgb(1, 2, 3)', 'replace', 'linear'),
+                            value(1, 'rgb(4, 5, 6)', 'replace') ] },
+                { property: 'border-right-color',
+                  values: [ value(0, 'rgb(7, 8, 9)', 'replace', 'linear'),
+                            value(1, 'rgb(10, 11, 12)', 'replace') ] },
+                { property: 'border-top-color',
+                  values: [ value(0, 'rgb(7, 8, 9)', 'replace', 'linear'),
+                            value(1, 'rgb(10, 11, 12)', 'replace') ] },
+                { property: 'border-bottom-width',
+                  values: [ value(0, '3px', 'replace', 'linear'),
+                            value(1, '4px', 'replace') ] },
+                { property: 'border-left-width',
+                  values: [ value(0, '1px', 'replace', 'linear'),
+                            value(1, '2px', 'replace') ] },
+                { property: 'border-right-width',
+                  values: [ value(0, '3px', 'replace', 'linear'),
+                            value(1, '4px', 'replace') ] },
+                { property: 'border-top-width',
+                  values: [ value(0, '3px', 'replace', 'linear'),
+                            value(1, '4px', 'replace') ] } ]
+  },
+
+  // ---------------------------------------------------------------------
+  //
+  // Tests for keyframe sequences
+  //
+  // ---------------------------------------------------------------------
+
+  { desc:     'a keyframe sequence specification with repeated values at'
+              + ' offset 0/1 with different easings',
+    frames:   [ { offset: 0.0, left: '100px', easing: 'ease' },
+                { offset: 0.0, left: '200px', easing: 'ease' },
+                { offset: 0.5, left: '300px', easing: 'linear' },
+                { offset: 1.0, left: '400px', easing: 'ease-out' },
+                { offset: 1.0, left: '500px', easing: 'step-end' } ],
+    expected: [ { property: 'left',
+                  values: [ value(0, '100px', 'replace'),
+                            value(0, '200px', 'replace', 'ease'),
+                            value(0.5, '300px', 'replace', 'linear'),
+                            value(1, '400px', 'replace'),
+                            value(1, '500px', 'replace') ] } ]
+  },
+  { desc:     'a one-property two-keyframe sequence',
+    frames:   [ { offset: 0, left: '10px' },
+                { offset: 1, left: '20px' } ],
+    expected: [ { property: 'left',
+                  values: [ value(0, '10px', 'replace', 'linear'),
+                            value(1, '20px', 'replace') ] } ]
+  },
+  { desc:     'a two-property two-keyframe sequence',
+    frames:   [ { offset: 0, left: '10px', top: '30px' },
+                { offset: 1, left: '20px', top: '40px' } ],
+    expected: [ { property: 'left',
+                  values: [ value(0, '10px', 'replace', 'linear'),
+                            value(1, '20px', 'replace') ] },
+                { property: 'top',
+                  values: [ value(0, '30px', 'replace', 'linear'),
+                            value(1, '40px', 'replace') ] } ]
+  },
+  { desc:     'a one shorthand property two-keyframe sequence',
+    frames:   [ { offset: 0, margin: '10px' },
+                { offset: 1, margin: '20px 30px 40px 50px' } ],
+    expected: [ { property: 'margin-top',
+                  values: [ value(0, '10px', 'replace', 'linear'),
+                            value(1, '20px', 'replace') ] },
+                { property: 'margin-right',
+                  values: [ value(0, '10px', 'replace', 'linear'),
+                            value(1, '30px', 'replace') ] },
+                { property: 'margin-bottom',
+                  values: [ value(0, '10px', 'replace', 'linear'),
+                            value(1, '40px', 'replace') ] },
+                { property: 'margin-left',
+                  values: [ value(0, '10px', 'replace', 'linear'),
+                            value(1, '50px', 'replace') ] } ]
+  },
+  { desc:     'a two-property (a shorthand and one of its component longhands)'
+              + ' two-keyframe sequence',
+    frames:   [ { offset: 0, margin: '10px', marginTop: '20px' },
+                { offset: 1, marginTop: '70px',
+                             margin: '30px 40px 50px 60px' } ],
+    expected: [ { property: 'margin-top',
+                  values: [ value(0, '20px', 'replace', 'linear'),
+                            value(1, '70px', 'replace') ] },
+                { property: 'margin-right',
+                  values: [ value(0, '10px', 'replace', 'linear'),
+                            value(1, '40px', 'replace') ] },
+                { property: 'margin-bottom',
+                  values: [ value(0, '10px', 'replace', 'linear'),
+                            value(1, '50px', 'replace') ] },
+                { property: 'margin-left',
+                  values: [ value(0, '10px', 'replace', 'linear'),
+                            value(1, '60px', 'replace') ] } ]
+  },
+  { desc:     'a keyframe sequence with duplicate values for a given interior'
+              + ' offset',
+    frames:   [ { offset: 0.0, left: '10px' },
+                { offset: 0.5, left: '20px' },
+                { offset: 0.5, left: '30px' },
+                { offset: 0.5, left: '40px' },
+                { offset: 1.0, left: '50px' } ],
+    expected: [ { property: 'left',
+                  values: [ value(0, '10px', 'replace', 'linear'),
+                            value(0.5, '20px', 'replace'),
+                            value(0.5, '40px', 'replace', 'linear'),
+                            value(1, '50px', 'replace') ] } ]
+  },
+  { desc:     'a keyframe sequence with duplicate values for offsets 0 and 1',
+    frames:   [ { offset: 0, left: '10px' },
+                { offset: 0, left: '20px' },
+                { offset: 0, left: '30px' },
+                { offset: 1, left: '40px' },
+                { offset: 1, left: '50px' },
+                { offset: 1, left: '60px' } ],
+    expected: [ { property: 'left',
+                  values: [ value(0, '10px', 'replace'),
+                            value(0, '30px', 'replace', 'linear'),
+                            value(1, '40px', 'replace'),
+                            value(1, '60px', 'replace') ] } ]
+  },
+  { desc:     'a two-property four-keyframe sequence',
+    frames:   [ { offset: 0, left: '10px' },
+                { offset: 0, top: '20px' },
+                { offset: 1, top: '30px' },
+                { offset: 1, left: '40px' } ],
+    expected: [ { property: 'left',
+                  values: [ value(0, '10px', 'replace', 'linear'),
+                            value(1, '40px', 'replace') ] },
+                { property: 'top',
+                  values: [ value(0, '20px', 'replace', 'linear'),
+                            value(1, '30px', 'replace') ] } ]
+  },
+  { desc:     'a one-property keyframe sequence with some omitted offsets',
+    frames:   [ { offset: 0.00, left: '10px' },
+                { offset: 0.25, left: '20px' },
+                { left: '30px' },
+                { left: '40px' },
+                { offset: 1.00, left: '50px' } ],
+    expected: [ { property: 'left',
+                  values: [ value(0, '10px', 'replace', 'linear'),
+                            value(0.25, '20px', 'replace', 'linear'),
+                            value(0.5, '30px', 'replace', 'linear'),
+                            value(0.75, '40px', 'replace', 'linear'),
+                            value(1, '50px', 'replace') ] } ]
+  },
+  { desc:     'a two-property keyframe sequence with some omitted offsets',
+    frames:   [ { offset: 0.00, left: '10px', top: '20px' },
+                { offset: 0.25, left: '30px' },
+                { left: '40px' },
+                { left: '50px', top: '60px' },
+                { offset: 1.00, left: '70px', top: '80px' } ],
+    expected: [ { property: 'left',
+                  values: [ value(0, '10px', 'replace', 'linear'),
+                            value(0.25, '30px', 'replace', 'linear'),
+                            value(0.5, '40px', 'replace', 'linear'),
+                            value(0.75, '50px', 'replace', 'linear'),
+                            value(1, '70px', 'replace') ] },
+                { property: 'top',
+                  values: [ value(0, '20px', 'replace', 'linear'),
+                            value(0.75, '60px', 'replace', 'linear'),
+                            value(1, '80px', 'replace') ] } ]
+  },
+  { desc:     'a one-property keyframe sequence with all omitted offsets',
+    frames:   [ { left: '10px' },
+                { left: '20px' },
+                { left: '30px' },
+                { left: '40px' },
+                { left: '50px' } ],
+    expected: [ { property: 'left',
+                  values: [ value(0, '10px', 'replace', 'linear'),
+                            value(0.25, '20px', 'replace', 'linear'),
+                            value(0.5, '30px', 'replace', 'linear'),
+                            value(0.75, '40px', 'replace', 'linear'),
+                            value(1, '50px', 'replace') ] } ]
+  },
+  { desc:     'a keyframe sequence with different easing values, but the'
+              + ' same easing value for a given offset',
+    frames:   [ { offset: 0.0, easing: 'ease',     left: '10px'},
+                { offset: 0.0, easing: 'ease',     top: '20px'},
+                { offset: 0.5, easing: 'linear',   left: '30px' },
+                { offset: 0.5, easing: 'linear',   top: '40px' },
+                { offset: 1.0, easing: 'step-end', left: '50px' },
+                { offset: 1.0, easing: 'step-end', top: '60px' } ],
+    expected: [ { property: 'left',
+                  values: [ value(0, '10px', 'replace', 'ease'),
+                            value(0.5, '30px', 'replace', 'linear'),
+                            value(1, '50px', 'replace') ] },
+                { property: 'top',
+                  values: [ value(0, '20px', 'replace', 'ease'),
+                            value(0.5, '40px', 'replace', 'linear'),
+                            value(1, '60px', 'replace') ] } ]
+  },
+  { desc:     'a one-property two-keyframe sequence that needs to'
+              + ' stringify its values',
+    frames:   [ { offset: 0, opacity: 0 },
+                { offset: 1, opacity: 1 } ],
+    expected: [ { property: 'opacity',
+                  values: [ value(0, '0', 'replace', 'linear'),
+                            value(1, '1', 'replace') ] } ]
+  },
+  { desc:     'a keyframe sequence where shorthand precedes longhand',
+    frames:   [ { offset: 0, margin: '10px', marginRight: '20px' },
+                { offset: 1, margin: '30px' } ],
+    expected: [ { property: 'margin-top',
+                  values: [ value(0, '10px', 'replace', 'linear'),
+                            value(1, '30px', 'replace') ] },
+                { property: 'margin-right',
+                  values: [ value(0, '20px', 'replace', 'linear'),
+                            value(1, '30px', 'replace') ] },
+                { property: 'margin-bottom',
+                  values: [ value(0, '10px', 'replace', 'linear'),
+                            value(1, '30px', 'replace') ] },
+                { property: 'margin-left',
+                  values: [ value(0, '10px', 'replace', 'linear'),
+                            value(1, '30px', 'replace') ] } ]
+  },
+  { desc:     'a keyframe sequence where longhand precedes shorthand',
+    frames:   [ { offset: 0, marginRight: '20px', margin: '10px' },
+                { offset: 1, margin: '30px' } ],
+    expected: [ { property: 'margin-top',
+                  values: [ value(0, '10px', 'replace', 'linear'),
+                            value(1, '30px', 'replace') ] },
+                { property: 'margin-right',
+                  values: [ value(0, '20px', 'replace', 'linear'),
+                            value(1, '30px', 'replace') ] },
+                { property: 'margin-bottom',
+                  values: [ value(0, '10px', 'replace', 'linear'),
+                            value(1, '30px', 'replace') ] },
+                { property: 'margin-left',
+                  values: [ value(0, '10px', 'replace', 'linear'),
+                            value(1, '30px', 'replace') ] } ]
+  },
+  { desc:     'a keyframe sequence where lesser shorthand precedes greater'
+              + ' shorthand',
+    frames:   [ { offset: 0, borderLeft: '1px solid rgb(1, 2, 3)',
+                             border: '2px dotted rgb(4, 5, 6)' },
+                { offset: 1, border: '3px dashed rgb(7, 8, 9)' } ],
+    expected: [ { property: 'border-bottom-color',
+                  values: [ value(0, 'rgb(4, 5, 6)', 'replace', 'linear'),
+                            value(1, 'rgb(7, 8, 9)', 'replace') ] },
+                { property: 'border-left-color',
+                  values: [ value(0, 'rgb(1, 2, 3)', 'replace', 'linear'),
+                            value(1, 'rgb(7, 8, 9)', 'replace') ] },
+                { property: 'border-right-color',
+                  values: [ value(0, 'rgb(4, 5, 6)', 'replace', 'linear'),
+                            value(1, 'rgb(7, 8, 9)', 'replace') ] },
+                { property: 'border-top-color',
+                  values: [ value(0, 'rgb(4, 5, 6)', 'replace', 'linear'),
+                            value(1, 'rgb(7, 8, 9)', 'replace') ] },
+                { property: 'border-bottom-width',
+                  values: [ value(0, '2px', 'replace', 'linear'),
+                            value(1, '3px', 'replace') ] },
+                { property: 'border-left-width',
+                  values: [ value(0, '1px', 'replace', 'linear'),
+                            value(1, '3px', 'replace') ] },
+                { property: 'border-right-width',
+                  values: [ value(0, '2px', 'replace', 'linear'),
+                            value(1, '3px', 'replace') ] },
+                { property: 'border-top-width',
+                  values: [ value(0, '2px', 'replace', 'linear'),
+                            value(1, '3px', 'replace') ] } ]
+  },
+  { desc:     'a keyframe sequence where greater shorthand precedes' +
+              + ' lesser shorthand',
+    frames:   [ { offset: 0, border: '2px dotted rgb(4, 5, 6)',
+                             borderLeft: '1px solid rgb(1, 2, 3)' },
+                { offset: 1, border: '3px dashed rgb(7, 8, 9)' } ],
+    expected: [ { property: 'border-bottom-color',
+                  values: [ value(0, 'rgb(4, 5, 6)', 'replace', 'linear'),
+                            value(1, 'rgb(7, 8, 9)', 'replace') ] },
+                { property: 'border-left-color',
+                  values: [ value(0, 'rgb(1, 2, 3)', 'replace', 'linear'),
+                            value(1, 'rgb(7, 8, 9)', 'replace') ] },
+                { property: 'border-right-color',
+                  values: [ value(0, 'rgb(4, 5, 6)', 'replace', 'linear'),
+                            value(1, 'rgb(7, 8, 9)', 'replace') ] },
+                { property: 'border-top-color',
+                  values: [ value(0, 'rgb(4, 5, 6)', 'replace', 'linear'),
+                            value(1, 'rgb(7, 8, 9)', 'replace') ] },
+                { property: 'border-bottom-width',
+                  values: [ value(0, '2px', 'replace', 'linear'),
+                            value(1, '3px', 'replace') ] },
+                { property: 'border-left-width',
+                  values: [ value(0, '1px', 'replace', 'linear'),
+                            value(1, '3px', 'replace') ] },
+                { property: 'border-right-width',
+                  values: [ value(0, '2px', 'replace', 'linear'),
+                            value(1, '3px', 'replace') ] },
+                { property: 'border-top-width',
+                  values: [ value(0, '2px', 'replace', 'linear'),
+                            value(1, '3px', 'replace') ] } ]
+  },
+
+  // ---------------------------------------------------------------------
+  //
+  // Tests for unit conversion
+  //
+  // ---------------------------------------------------------------------
+
+  { desc:     'em units are resolved to px values',
+    frames:   { left: ['10em', '20em'] },
+    expected: [ { property: 'left',
+                  values: [ value(0, '100px', 'replace', 'linear'),
+                            value(1, '200px', 'replace') ] } ]
+  }
+];
+
+gTests.forEach(function(subtest) {
+  test(function(t) {
+    var div = addDiv(t);
+    var animation = div.animate(subtest.frames, 1000);
+    assert_properties_equal(animation.effect.getProperties(),
+                            subtest.expected);
+  }, subtest.desc);
+});
+
+</script>
+</body>
diff --git a/dom/animation/test/chrome/test_animation_property_state.html b/dom/animation/test/chrome/test_animation_property_state.html
index 0dcce0200d..a2129e29c9 100644
--- a/dom/animation/test/chrome/test_animation_property_state.html
+++ b/dom/animation/test/chrome/test_animation_property_state.html
@@ -1,8 +1,8 @@
 <!doctype html>
 <head>
 <meta charset=utf-8>
-<title>Bug 1196114 - Animation property which indicates
-       running on the compositor or not</title>
+<title>Bug 1196114 - Test metadata related to which animation properties
+       are running on the compositor</title>
 <script type="application/javascript" src="../testharness.js"></script>
 <script type="application/javascript" src="../testharnessreport.js"></script>
 <script type="application/javascript" src="../testcommon.js"></script>
@@ -13,6 +13,10 @@
   height: 100px;
   background-color: white;
 }
+@keyframes fade {
+  from { opacity: 1 }
+  to   { opacity: 0 }
+}
 </style>
 </head>
 <body>
@@ -41,7 +45,7 @@ function compare_property_state(a, b) {
 }
 
 function assert_animation_property_state_equals(actual, expected) {
-  assert_equals(actual.length, expected.length);
+  assert_equals(actual.length, expected.length, 'Number of properties');
 
   var sortedActual = actual.sort(compare_property_state);
   var sortedExpected = expected.sort(compare_property_state);
@@ -79,7 +83,8 @@ function assert_property_state_on_compositor(actual, expected) {
                   sortedExpected[i].property,
                   'CSS property name should match');
     assert_true(sortedActual[i].runningOnCompositor,
-                'runningOnCompositor property should be true');
+                'runningOnCompositor property should be true on ' +
+                sortedActual[i].property);
     assert_not_exists(sortedActual[i], 'warning',
                       'warning property should not be set');
   }
@@ -144,11 +149,28 @@ var gAnimationsTests = [
       }
     ]
   },
+  {
+    desc: 'opacity on compositor with animation of geometric properties',
+    frames: {
+      width: ['100px', '200px'],
+      opacity: [0, 1]
+    },
+    expected: [
+      {
+        property: 'width',
+        runningOnCompositor: false
+      },
+      {
+        property: 'opacity',
+        runningOnCompositor: true
+      }
+    ]
+  },
   {
     // FIXME: Once we have KeyframeEffect.setFrames, we should rewrite
     // this test case to check that runningOnCompositor is restored to true
     // after 'width' keyframe is removed from the keyframes.
-    desc: 'animation on compositor with animation of geometric properties',
+    desc: 'transform on compositor with animation of geometric properties',
     frames: {
       width: ['100px', '200px'],
       transform: ['translate(0px)', 'translate(100px)']
@@ -161,7 +183,31 @@ var gAnimationsTests = [
       {
         property: 'transform',
         runningOnCompositor: false,
-        warning: 'AnimationWarningWithGeometricProperties'
+        warning: 'AnimationWarningTransformWithGeometricProperties'
+      }
+    ]
+  },
+  {
+    desc: 'opacity and transform on compositor with animation of geometric ' +
+          'properties',
+    frames: {
+      width: ['100px', '200px'],
+      opacity: [0, 1],
+      transform: ['translate(0px)', 'translate(100px)']
+    },
+    expected: [
+      {
+        property: 'width',
+        runningOnCompositor: false
+      },
+      {
+        property: 'opacity',
+        runningOnCompositor: true
+      },
+      {
+        property: 'transform',
+        runningOnCompositor: false,
+        warning: 'AnimationWarningTransformWithGeometricProperties'
       }
     ]
   },
@@ -173,7 +219,7 @@ gAnimationsTests.forEach(function(subtest) {
     var animation = div.animate(subtest.frames, 100000);
     return animation.ready.then(t.step_func(function() {
       assert_animation_property_state_equals(
-        animation.effect.getPropertyState(),
+        animation.effect.getProperties(),
         subtest.expected);
     }));
   }, subtest.desc);
@@ -208,6 +254,243 @@ var gPerformanceWarningTests = [
       }
     ]
   },
+  {
+    desc: 'opacity and transform with preserve-3d',
+    frames: {
+      opacity: [0, 1],
+      transform: ['translate(0px)', 'translate(100px)']
+    },
+    style: 'transform-style: preserve-3d',
+    expected: [
+      {
+        property: 'opacity',
+        runningOnCompositor: true
+      },
+      {
+        property: 'transform',
+        runningOnCompositor: false,
+        warning: 'AnimationWarningTransformPreserve3D'
+      }
+    ]
+  },
+  {
+    desc: 'opacity and transform with backface-visibility:hidden',
+    frames: {
+      opacity: [0, 1],
+      transform: ['translate(0px)', 'translate(100px)']
+    },
+    style: 'backface-visibility: hidden;',
+    expected: [
+      {
+        property: 'opacity',
+        runningOnCompositor: true
+      },
+      {
+        property: 'transform',
+        runningOnCompositor: false,
+        warning: 'AnimationWarningTransformBackfaceVisibilityHidden'
+      }
+    ]
+  },
+];
+
+var gMultipleAsyncAnimationsTests = [
+  {
+    desc: 'opacity and transform with preserve-3d',
+    style: 'transform-style: preserve-3d',
+    animations: [
+      {
+        frames: {
+          transform: ['translate(0px)', 'translate(100px)']
+        },
+        expected: [
+          {
+            property: 'transform',
+            runningOnCompositor: false,
+            warning: 'AnimationWarningTransformPreserve3D'
+          }
+        ]
+      },
+      {
+        frames: {
+          opacity: [0, 1]
+        },
+        expected: [
+          {
+            property: 'opacity',
+            runningOnCompositor: true,
+          }
+        ]
+      }
+    ],
+  },
+  {
+    desc: 'opacity and transform with backface-visibility:hidden',
+    style: 'backface-visibility: hidden;',
+    animations: [
+      {
+        frames: {
+          transform: ['translate(0px)', 'translate(100px)']
+        },
+        expected: [
+          {
+            property: 'transform',
+            runningOnCompositor: false,
+            warning: 'AnimationWarningTransformBackfaceVisibilityHidden'
+          }
+        ]
+      },
+      {
+        frames: {
+          opacity: [0, 1]
+        },
+        expected: [
+          {
+            property: 'opacity',
+            runningOnCompositor: true,
+          }
+        ]
+      }
+    ],
+  },
+];
+
+// FIXME: Once we have KeyframeEffect.setFrames, we should rewrite
+// these test cases to check that runningOnCompositor is restored to true
+// after 'width' keyframe is removed from the keyframes.
+var gMultipleAsyncAnimationsWithGeometricKeyframeTests = [
+  {
+    desc: 'transform and opacity with animation of geometric properties',
+    animations: [
+      {
+        frames: {
+          transform: ['translate(0px)', 'translate(100px)']
+        },
+        expected: [
+          {
+            property: 'transform',
+            runningOnCompositor: false,
+            warning: 'AnimationWarningTransformWithGeometricProperties'
+          }
+        ]
+      },
+      {
+        frames: {
+          width: ['100px', '200px'],
+          opacity: [0, 1]
+        },
+        expected: [
+          {
+            property: 'width',
+            runningOnCompositor: false,
+          },
+          {
+            property: 'opacity',
+            runningOnCompositor: true,
+          }
+        ]
+      }
+    ],
+  },
+  {
+    desc: 'opacity and transform with animation of geometric properties',
+    animations: [
+      {
+        frames: {
+          width: ['100px', '200px'],
+          transform: ['translate(0px)', 'translate(100px)']
+        },
+        expected: [
+          {
+            property: 'width',
+            runningOnCompositor: false,
+          },
+          {
+            property: 'transform',
+            runningOnCompositor: false,
+            warning: 'AnimationWarningTransformWithGeometricProperties'
+          }
+        ]
+      },
+      {
+        frames: {
+          opacity: [0, 1]
+        },
+        expected: [
+          {
+            property: 'opacity',
+            runningOnCompositor: true,
+          }
+        ]
+      }
+    ],
+  },
+];
+
+// Test cases that check results of adding/removing 'width' animation on the
+// same element which has async animations.
+var gMultipleAsyncAnimationsWithGeometricAnimationTests = [
+  {
+    desc: 'transform',
+    animations: [
+      {
+        frames: {
+          transform: ['translate(0px)', 'translate(100px)']
+        },
+        expected: [
+          {
+            property: 'transform',
+            runningOnCompositor: false,
+            warning: 'AnimationWarningTransformWithGeometricProperties'
+          }
+        ]
+      },
+    ]
+  },
+  {
+    desc: 'opacity',
+    animations: [
+      {
+        frames: {
+          opacity: [0, 1]
+        },
+        expected: [
+          {
+            property: 'opacity',
+            runningOnCompositor: true
+          }
+        ]
+      },
+    ]
+  },
+  {
+    desc: 'opacity and transform',
+    animations: [
+      {
+        frames: {
+          transform: ['translate(0px)', 'translate(100px)']
+        },
+        expected: [
+          {
+            property: 'transform',
+            runningOnCompositor: false,
+            warning: 'AnimationWarningTransformWithGeometricProperties'
+          }
+        ]
+      },
+      {
+        frames: {
+          opacity: [0, 1]
+        },
+        expected: [
+          {
+            property: 'opacity',
+            runningOnCompositor: true,
+          }
+        ]
+      }
+    ],
+  },
 ];
 
 function start() {
@@ -222,7 +505,7 @@ function start() {
       var animation = div.animate(subtest.frames, 100000);
       return animation.ready.then(t.step_func(function() {
         assert_animation_property_state_equals(
-          animation.effect.getPropertyState(),
+          animation.effect.getProperties(),
           subtest.expected);
       }));
     }, subtest.desc);
@@ -234,31 +517,132 @@ function start() {
       var animation = div.animate(subtest.frames, 100000);
       return animation.ready.then(t.step_func(function() {
         assert_property_state_on_compositor(
-          animation.effect.getPropertyState(),
+          animation.effect.getProperties(),
           subtest.expected);
         div.style = subtest.style;
         return waitForFrame();
       })).then(t.step_func(function() {
         assert_animation_property_state_equals(
-          animation.effect.getPropertyState(),
+          animation.effect.getProperties(),
           subtest.expected);
         div.style = '';
         return waitForFrame();
       })).then(t.step_func(function() {
         assert_property_state_on_compositor(
-          animation.effect.getPropertyState(),
+          animation.effect.getProperties(),
           subtest.expected);
       }));
     }, subtest.desc);
   });
 
+  gMultipleAsyncAnimationsTests.forEach(function(subtest) {
+    promise_test(function(t) {
+      var div = addDiv(t, { class: 'compositable' });
+      var animations = subtest.animations.map(function(anim) {
+        var animation = div.animate(anim.frames, 100000);
+
+        // Bind expected values to animation object.
+        animation.expected = anim.expected;
+        return animation;
+      });
+      return waitForAllAnimations(animations).then(t.step_func(function() {
+        animations.forEach(t.step_func(function(anim) {
+          assert_property_state_on_compositor(
+            anim.effect.getProperties(),
+            anim.expected);
+        }));
+        div.style = subtest.style;
+        return waitForFrame();
+      })).then(t.step_func(function() {
+        animations.forEach(t.step_func(function(anim) {
+          assert_animation_property_state_equals(
+            anim.effect.getProperties(),
+            anim.expected);
+        }));
+        div.style = '';
+        return waitForFrame();
+      })).then(t.step_func(function() {
+        animations.forEach(t.step_func(function(anim) {
+          assert_property_state_on_compositor(
+            anim.effect.getProperties(),
+            anim.expected);
+        }));
+      }));
+    }, 'Multiple animations: ' + subtest.desc);
+  });
+
+  gMultipleAsyncAnimationsWithGeometricKeyframeTests.forEach(function(subtest) {
+    promise_test(function(t) {
+      var div = addDiv(t, { class: 'compositable' });
+      var animations = subtest.animations.map(function(anim) {
+        var animation = div.animate(anim.frames, 100000);
+
+        // Bind expected values to animation object.
+        animation.expected = anim.expected;
+        return animation;
+      });
+      return waitForAllAnimations(animations).then(t.step_func(function() {
+        animations.forEach(t.step_func(function(anim) {
+          assert_animation_property_state_equals(
+            anim.effect.getProperties(),
+            anim.expected);
+        }));
+      }));
+    }, 'Multiple animations with geometric property: ' + subtest.desc);
+  });
+
+  gMultipleAsyncAnimationsWithGeometricAnimationTests.forEach(function(subtest) {
+    promise_test(function(t) {
+      var div = addDiv(t, { class: 'compositable' });
+      var animations = subtest.animations.map(function(anim) {
+        var animation = div.animate(anim.frames, 100000);
+
+        // Bind expected values to animation object.
+        animation.expected = anim.expected;
+        return animation;
+      });
+
+      var widthAnimation;
+
+      return waitForAllAnimations(animations).then(t.step_func(function() {
+        animations.forEach(t.step_func(function(anim) {
+          assert_property_state_on_compositor(
+            anim.effect.getProperties(),
+            anim.expected);
+        }));
+      })).then(t.step_func(function() {
+        // Append 'width' animation on the same element.
+        widthAnimation = div.animate({ width: ['100px', '200px'] }, 100000);
+        return waitForFrame();
+      })).then(t.step_func(function() {
+        // Now transform animations are not running on compositor because of
+        // the 'width' animation.
+        animations.forEach(t.step_func(function(anim) {
+          assert_animation_property_state_equals(
+            anim.effect.getProperties(),
+            anim.expected);
+        }));
+        // Remove the 'width' animation.
+        widthAnimation.cancel();
+        return waitForFrame();
+      })).then(t.step_func(function() {
+        // Now all animations are running on compositor.
+        animations.forEach(t.step_func(function(anim) {
+          assert_property_state_on_compositor(
+            anim.effect.getProperties(),
+            anim.expected);
+        }));
+      }));
+    }, 'Multiple async animations and geometric animation: ' + subtest.desc);
+  });
+
   promise_test(function(t) {
     var div = addDiv(t, { class: 'compositable' });
     var animation = div.animate(
       { transform: ['translate(0px)', 'translate(100px)'] }, 100000);
     return animation.ready.then(t.step_func(function() {
       assert_animation_property_state_equals(
-        animation.effect.getPropertyState(),
+        animation.effect.getProperties(),
         [ { property: 'transform', runningOnCompositor: true } ]);
       div.style = 'width: 10000px; height: 10000px';
       return waitForFrame();
@@ -269,7 +653,7 @@ function start() {
         "bigger than the viewport \\(\\d+, \\d+\\) or the visual rectangle " +
         "\\(10000, 10000\\) is larger than the max allowed value \\(\\d+\\)");
       assert_animation_property_state_equals(
-        animation.effect.getPropertyState(),
+        animation.effect.getProperties(),
         [ {
           property: 'transform',
           runningOnCompositor: false,
@@ -280,7 +664,7 @@ function start() {
     })).then(t.step_func(function() {
       // FIXME: Bug 1253164: the animation should get back on compositor.
       assert_animation_property_state_equals(
-        animation.effect.getPropertyState(),
+        animation.effect.getProperties(),
         [ { property: 'transform', runningOnCompositor: false } ]);
     }));
   }, 'transform on too big element');
@@ -303,13 +687,13 @@ function start() {
       { transform: ['translate(0px)', 'translate(100px)'] }, 100000);
     return animation.ready.then(t.step_func(function() {
       assert_animation_property_state_equals(
-        animation.effect.getPropertyState(),
+        animation.effect.getProperties(),
         [ { property: 'transform', runningOnCompositor: true } ]);
       svg.setAttribute('transform', 'translate(10, 20)');
       return waitForFrame();
     })).then(t.step_func(function() {
       assert_animation_property_state_equals(
-        animation.effect.getPropertyState(),
+        animation.effect.getProperties(),
         [ {
           property: 'transform',
           runningOnCompositor: false,
@@ -319,10 +703,25 @@ function start() {
       return waitForFrame();
     })).then(t.step_func(function() {
       assert_animation_property_state_equals(
-        animation.effect.getPropertyState(),
+        animation.effect.getProperties(),
         [ { property: 'transform', runningOnCompositor: true } ]);
     }));
   }, 'transform of nsIFrame with SVG transform');
+
+  promise_test(function(t) {
+    var div = addDiv(t, { class: 'compositable',
+                          style: 'animation: fade 100s' });
+    var cssAnimation = div.getAnimations()[0];
+    var scriptAnimation = div.animate({ opacity: [ 1, 0 ] }, 1000);
+    return scriptAnimation.ready.then(function() {
+      assert_animation_property_state_equals(
+        cssAnimation.effect.getProperties(),
+        [ { property: 'opacity', runningOnCompositor: false } ]);
+      assert_animation_property_state_equals(
+        scriptAnimation.effect.getProperties(),
+        [ { property: 'opacity', runningOnCompositor: true } ]);
+    });
+  }, 'overridden animation');
 }
 
 </script>
diff --git a/dom/base/DOMRequest.cpp b/dom/base/DOMRequest.cpp
index 1f31874da4..2d791525b5 100644
--- a/dom/base/DOMRequest.cpp
+++ b/dom/base/DOMRequest.cpp
@@ -14,6 +14,7 @@
 #include "mozilla/dom/Promise.h"
 #include "mozilla/dom/ScriptSettings.h"
 #include "jsfriendapi.h"
+#include "nsContentUtils.h"
 
 using mozilla::dom::AnyCallback;
 using mozilla::dom::DOMError;
@@ -298,11 +299,10 @@ DOMRequestService::FireDetailedError(nsIDOMDOMRequest* aRequest,
 class FireSuccessAsyncTask : public nsRunnable
 {
 
-  FireSuccessAsyncTask(JSContext* aCx,
-                       DOMRequest* aRequest,
+  FireSuccessAsyncTask(DOMRequest* aRequest,
                        const JS::Value& aResult) :
     mReq(aRequest),
-    mResult(aCx, aResult)
+    mResult(nsContentUtils::RootingCxForThread(), aResult)
   {
   }
 
@@ -315,8 +315,8 @@ public:
   Dispatch(DOMRequest* aRequest,
            const JS::Value& aResult)
   {
-    mozilla::ThreadsafeAutoSafeJSContext cx;
-    RefPtr<FireSuccessAsyncTask> asyncTask = new FireSuccessAsyncTask(cx, aRequest, aResult);
+    RefPtr<FireSuccessAsyncTask> asyncTask =
+      new FireSuccessAsyncTask(aRequest, aResult);
     MOZ_ALWAYS_TRUE(NS_SUCCEEDED(NS_DispatchToCurrentThread(asyncTask)));
     return NS_OK;
   }
diff --git a/dom/base/Element.cpp b/dom/base/Element.cpp
index 5b981c2fb3..34ebeb3cc0 100644
--- a/dom/base/Element.cpp
+++ b/dom/base/Element.cpp
@@ -3425,14 +3425,8 @@ Element::Animate(const Nullable<ElementOrCSSPseudoElement>& aTarget,
     }
   }
 
-  TimingParams timingParams =
-    TimingParams::FromOptionsUnion(aOptions, aTarget, aError);
-  if (aError.Failed()) {
-    return nullptr;
-  }
-
   RefPtr<KeyframeEffect> effect =
-    KeyframeEffect::Constructor(global, aTarget, frames, timingParams, aError);
+    KeyframeEffect::Constructor(global, aTarget, frames, aOptions, aError);
   if (aError.Failed()) {
     return nullptr;
   }
diff --git a/dom/base/Navigator.h b/dom/base/Navigator.h
index 50105cf85c..74703d628a 100644
--- a/dom/base/Navigator.h
+++ b/dom/base/Navigator.h
@@ -149,6 +149,10 @@ public:
 
   // The XPCOM GetProduct is OK
   // The XPCOM GetLanguage is OK
+  void GetUserAgent(nsString& aUserAgent, ErrorResult& /* unused */)
+  {
+    GetUserAgent(aUserAgent);
+  }
   bool OnLine();
   void RegisterProtocolHandler(const nsAString& aScheme, const nsAString& aURL,
                                const nsAString& aTitle, ErrorResult& aRv);
diff --git a/dom/base/ScriptSettings.cpp b/dom/base/ScriptSettings.cpp
index f79e173e0b..057d643725 100644
--- a/dom/base/ScriptSettings.cpp
+++ b/dom/base/ScriptSettings.cpp
@@ -883,26 +883,4 @@ AutoSafeJSContext::AutoSafeJSContext(MOZ_GUARD_OBJECT_NOTIFIER_ONLY_PARAM_IN_IMP
              "returned null, and inited correctly otherwise!");
 }
 
-ThreadsafeAutoSafeJSContext::ThreadsafeAutoSafeJSContext(MOZ_GUARD_OBJECT_NOTIFIER_ONLY_PARAM_IN_IMPL)
-{
-  MOZ_GUARD_OBJECT_NOTIFIER_INIT;
-
-  if (NS_IsMainThread()) {
-    mCx = nullptr;
-    mAutoSafeJSContext.emplace();
-  } else {
-    mCx = mozilla::dom::workers::GetCurrentThreadJSContext();
-    mRequest.emplace(mCx);
-  }
-}
-
-ThreadsafeAutoSafeJSContext::operator JSContext*() const
-{
-  if (mCx) {
-    return mCx;
-  } else {
-    return *mAutoSafeJSContext;
-  }
-}
-
 } // namespace mozilla
diff --git a/dom/base/ScriptSettings.h b/dom/base/ScriptSettings.h
index 7264347e7e..4236e7fa8f 100644
--- a/dom/base/ScriptSettings.h
+++ b/dom/base/ScriptSettings.h
@@ -477,22 +477,6 @@ private:
   MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
 };
 
-/**
- * Like AutoSafeJSContext but can be used safely on worker threads.
- */
-class MOZ_RAII ThreadsafeAutoSafeJSContext {
-public:
-  explicit ThreadsafeAutoSafeJSContext(MOZ_GUARD_OBJECT_NOTIFIER_ONLY_PARAM);
-  operator JSContext*() const;
-
-private:
-  JSContext* mCx; // Used on workers.  Null means mainthread.
-  Maybe<JSAutoRequest> mRequest; // Used on workers.
-  Maybe<AutoSafeJSContext> mAutoSafeJSContext; // Used on main thread.
-  MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER
-};
-
-
 } // namespace mozilla
 
 #endif // mozilla_dom_ScriptSettings_h
diff --git a/dom/bindings/Bindings.conf b/dom/bindings/Bindings.conf
index c00bf1e3a7..00d74de551 100644
--- a/dom/bindings/Bindings.conf
+++ b/dom/bindings/Bindings.conf
@@ -511,7 +511,6 @@ DOMInterfaces = {
 },
 
 'FileReaderSync': {
-    'workers': True,
     'wrapperCache': False,
 },
 
@@ -1620,14 +1619,7 @@ DOMInterfaces = {
     },
 },
 
-'WorkerLocation': {
-    'headerFile': 'mozilla/dom/workers/bindings/Location.h',
-    'workers': True,
-},
-
 'WorkerNavigator': {
-    'headerFile': 'mozilla/dom/workers/bindings/Navigator.h',
-    'workers': True,
     'implicitJSContext': ['getDataStores'],
 },
 
diff --git a/dom/events/CustomEvent.cpp b/dom/events/CustomEvent.cpp
index 0094b4124a..a6197e0400 100644
--- a/dom/events/CustomEvent.cpp
+++ b/dom/events/CustomEvent.cpp
@@ -17,21 +17,30 @@ using namespace mozilla::dom;
 CustomEvent::CustomEvent(mozilla::dom::EventTarget* aOwner,
                          nsPresContext* aPresContext,
                          mozilla::WidgetEvent* aEvent)
-: Event(aOwner, aPresContext, aEvent)
+  : Event(aOwner, aPresContext, aEvent)
+  , mDetail(JS::NullValue())
 {
+  mozilla::HoldJSObjects(this);
 }
 
-CustomEvent::~CustomEvent() {}
+CustomEvent::~CustomEvent()
+{
+  mozilla::DropJSObjects(this);
+}
 
 NS_IMPL_CYCLE_COLLECTION_CLASS(CustomEvent)
 NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(CustomEvent, Event)
-  NS_IMPL_CYCLE_COLLECTION_UNLINK(mDetail)
+  tmp->mDetail.setUndefined();
+  mozilla::DropJSObjects(this);
 NS_IMPL_CYCLE_COLLECTION_UNLINK_END
 
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(CustomEvent, Event)
-  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mDetail)
 NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END
 
+NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN_INHERITED(CustomEvent, Event)
+  NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mDetail)
+NS_IMPL_CYCLE_COLLECTION_TRACE_END
+
 NS_IMPL_ADDREF_INHERITED(CustomEvent, Event)
 NS_IMPL_RELEASE_INHERITED(CustomEvent, Event)
 
@@ -66,8 +75,21 @@ CustomEvent::InitCustomEvent(const nsAString& aType,
                              bool aCancelable,
                              nsIVariant* aDetail)
 {
+  AutoJSAPI jsapi;
+  NS_ENSURE_STATE(jsapi.Init(GetParentObject()));
+  JSContext* cx = jsapi.cx();
+  JS::Rooted<JS::Value> detail(cx);
+
+  if (!aDetail) {
+    detail = JS::NullValue();
+  } else if (NS_WARN_IF(!VariantToJsval(cx, aDetail, &detail))) {
+    JS_ClearPendingException(cx);
+    return NS_ERROR_FAILURE;
+  }
+
   Event::InitEvent(aType, aCanBubble, aCancelable);
-  mDetail = aDetail;
+  mDetail = detail;
+
   return NS_OK;
 }
 
@@ -79,35 +101,36 @@ CustomEvent::InitCustomEvent(JSContext* aCx,
                              JS::Handle<JS::Value> aDetail,
                              ErrorResult& aRv)
 {
-  nsCOMPtr<nsIVariant> detail;
-  if (nsIXPConnect* xpc = nsContentUtils::XPConnect()) {
-    xpc->JSToVariant(aCx, aDetail, getter_AddRefs(detail));
-  }
-
-  if (!detail) {
-    aRv.Throw(NS_ERROR_FAILURE);
-    return;
-  }
-  InitCustomEvent(aType, aCanBubble, aCancelable, detail);
+  Event::InitEvent(aType, aCanBubble, aCancelable);
+  mDetail = aDetail;
 }
 
 NS_IMETHODIMP
 CustomEvent::GetDetail(nsIVariant** aDetail)
 {
-  NS_IF_ADDREF(*aDetail = mDetail);
-  return NS_OK;
+  if (mDetail.isNull()) {
+    *aDetail = nullptr;
+    return NS_OK;
+  }
+
+  AutoJSAPI jsapi;
+  NS_ENSURE_STATE(jsapi.Init(GetParentObject()));
+  JSContext* cx = jsapi.cx();
+  JS::Rooted<JS::Value> detail(cx, mDetail);
+  nsIXPConnect* xpc = nsContentUtils::XPConnect();
+
+  if (NS_WARN_IF(!xpc)) {
+    return NS_ERROR_FAILURE;
+  }
+
+  return xpc->JSToVariant(cx, detail, aDetail);
 }
 
 void
 CustomEvent::GetDetail(JSContext* aCx,
                        JS::MutableHandle<JS::Value> aRetval)
 {
-  if (!mDetail) {
-    aRetval.setNull();
-    return;
-  }
-
-  VariantToJsval(aCx, mDetail, aRetval);
+  aRetval.set(mDetail);
 }
 
 already_AddRefed<CustomEvent>
diff --git a/dom/events/CustomEvent.h b/dom/events/CustomEvent.h
index 24cd0efa0e..d14243cff0 100644
--- a/dom/events/CustomEvent.h
+++ b/dom/events/CustomEvent.h
@@ -21,7 +21,7 @@ class CustomEvent final : public Event,
 private:
   virtual ~CustomEvent();
 
-  nsCOMPtr<nsIVariant> mDetail;
+  JS::Heap<JS::Value> mDetail;
 
 public:
   explicit CustomEvent(mozilla::dom::EventTarget* aOwner,
@@ -29,7 +29,7 @@ public:
                        mozilla::WidgetEvent* aEvent = nullptr);
 
   NS_DECL_ISUPPORTS_INHERITED
-  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(CustomEvent, Event)
+  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS_INHERITED(CustomEvent, Event)
   NS_FORWARD_TO_EVENT
   NS_DECL_NSIDOMCUSTOMEVENT
 
diff --git a/dom/events/test/mochitest.ini b/dom/events/test/mochitest.ini
index 51e894c205..198a1c471a 100644
--- a/dom/events/test/mochitest.ini
+++ b/dom/events/test/mochitest.ini
@@ -47,6 +47,8 @@ skip-if = buildapp == 'b2g' || e10s # b2g(2 failures out of 8, mousewheel test)
 [test_bug426082.html]
 skip-if = buildapp == 'mulet' || buildapp == 'b2g' || os == "win" || toolkit == 'android' || e10s # Intermittent failures, bug 921693 # b2g(1 failure out of 6, Moving the mouse down from the label should have unpressed the button) b2g-debug(1 failure out of 6, Moving the mouse down from the label should have unpressed the button) b2g-desktop(1 failure out of 6, Moving the mouse down from the label should have unpressed the button)
 [test_bug427537.html]
+[test_bug1003432.html]
+support-files = test_bug1003432.js
 [test_bug428988.html]
 [test_bug432698.html]
 skip-if = buildapp == 'mulet'
diff --git a/dom/events/test/test_bug1003432.html b/dom/events/test/test_bug1003432.html
new file mode 100644
index 0000000000..7ffd3f7c4c
--- /dev/null
+++ b/dom/events/test/test_bug1003432.html
@@ -0,0 +1,45 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=1003432
+-->
+<head>
+  <title>Test for Bug 1003432</title>
+  <script type="application/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
+</head>
+<body>
+<a target="_blank" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1003432">Mozilla Bug 1003432</a>
+<p id="display"></p>
+<div id="content" style="display: none">
+
+</div>
+<pre id="test">
+<script type="application/javascript">
+
+/** Test for Bug 1003432 **/
+// Test CustomEvent on worker
+SimpleTest.waitForExplicitFinish();
+var worker = new Worker("test_bug1003432.js");
+ok(worker, "Should have worker!");
+
+var count = 0;
+worker.onmessage = function(evt) {
+  is(evt.data.type, "foobar", "Should get 'foobar' event!");
+  is(evt.data.detail, "test", "Detail should be 'test'.");
+  ok(evt.data.bubbles, "Event should bubble!");
+  ok(evt.data.cancelable, "Event should be cancelable.");
+
+  // wait for test results of constructor and initCustomEvent
+  if (++count == 2) {
+    worker.terminate();
+    SimpleTest.finish();
+  }
+};
+
+worker.postMessage("");
+
+</script>
+</pre>
+</body>
+</html>
diff --git a/dom/events/test/test_bug1003432.js b/dom/events/test/test_bug1003432.js
new file mode 100644
index 0000000000..1ace8fefd7
--- /dev/null
+++ b/dom/events/test/test_bug1003432.js
@@ -0,0 +1,23 @@
+addEventListener("foobar",
+  function(evt) {
+    postMessage(
+      {
+        type: evt.type,
+        bubbles: evt.bubbles,
+        cancelable: evt.cancelable,
+        detail: evt.detail
+      });
+  }, true);
+
+addEventListener("message",
+  function(evt) {
+    // Test the constructor of CustomEvent
+    var e = new CustomEvent("foobar",
+      {bubbles:true, cancelable: true, detail:"test"});
+    dispatchEvent(e);
+
+    // Test initCustomEvent
+    e = new CustomEvent("foobar");
+    e.initCustomEvent("foobar", true, true, "test");
+    dispatchEvent(e);
+  }, true);
diff --git a/dom/events/test/test_bug427537.html b/dom/events/test/test_bug427537.html
index 6ca1a4c8a8..060581f2f6 100644
--- a/dom/events/test/test_bug427537.html
+++ b/dom/events/test/test_bug427537.html
@@ -39,6 +39,10 @@ document.addEventListener("foobar",
 document.dispatchEvent(e);
 ok(didCallListener, "Should have called listener!");
 
+e = document.createEvent("CustomEvent");
+e.initEvent("foo", true, true);
+is(e.detail, null, "Default detail should be null.");
+
 e = document.createEvent("CustomEvent");
 e.initCustomEvent("foobar", true, true, 1);
 is(e.detail, 1, "Detail should be 1.");
diff --git a/dom/locales/en-US/chrome/layout/layout_errors.properties b/dom/locales/en-US/chrome/layout/layout_errors.properties
index 7ae736b25d..e43bcd7c84 100644
--- a/dom/locales/en-US/chrome/layout/layout_errors.properties
+++ b/dom/locales/en-US/chrome/layout/layout_errors.properties
@@ -24,11 +24,11 @@ AnimationWarningTransformBackfaceVisibilityHidden=Async animation of 'backface-v
 ## 'transform-style: preserve-3d' is a CSS property, don't translate it.
 AnimationWarningTransformPreserve3D=Async animation of 'transform-style: preserve-3d' transforms is not supported
 ## LOCALIZATION NOTE(AnimationWarningTransformSVG,
+##                   AnimationWarningTransformWithGeometricProperties,
 ##                   AnimationWarningTransformFrameInactive,
-##                   AnimationWarningOpacityFrameInactive,
-##                   AnimationWarningWithGeometricProperties):
+##                   AnimationWarningOpacityFrameInactive):
 ## 'transform' and 'opacity' mean CSS property names, don't translate it.
 AnimationWarningTransformSVG=Async 'transform' animations of aFrames with SVG transforms is not supported
+AnimationWarningTransformWithGeometricProperties=Async animation of 'transform' not possible due to animation of geometric properties on the same element
 AnimationWarningTransformFrameInactive=Async animation disabled because frame was not marked active for 'transform' animation
 AnimationWarningOpacityFrameInactive=Async animation disabled because frame was not marked active for 'opacity' animation
-AnimationWarningWithGeometricProperties=Async animation of 'transform' or 'opacity' not possible due to animation of geometric properties on the same element
diff --git a/dom/promise/Promise.cpp b/dom/promise/Promise.cpp
index cb93c03cad..079ade8015 100644
--- a/dom/promise/Promise.cpp
+++ b/dom/promise/Promise.cpp
@@ -1762,21 +1762,21 @@ public:
   {
     MOZ_ASSERT(mCountdown > 0);
 
-    ThreadsafeAutoSafeJSContext cx;
-    JSAutoCompartment ac(cx, mValues);
-    {
+    AutoJSAPI jsapi;
+    if (!jsapi.Init(mValues)) {
+      return;
+    }
+    jsapi.TakeOwnershipOfErrorReporting();
+    JSContext* cx = jsapi.cx();
 
-      AutoDontReportUncaught silenceReporting(cx);
-      JS::Rooted<JS::Value> value(cx, aValue);
-      JS::Rooted<JSObject*> values(cx, mValues);
-      if (!JS_WrapValue(cx, &value) ||
-          !JS_DefineElement(cx, values, index, value, JSPROP_ENUMERATE)) {
-        MOZ_ASSERT(JS_IsExceptionPending(cx));
-        JS::Rooted<JS::Value> exn(cx);
-        JS_GetPendingException(cx, &exn);
-
-        mPromise->MaybeReject(cx, exn);
-      }
+    JS::Rooted<JS::Value> value(cx, aValue);
+    JS::Rooted<JSObject*> values(cx, mValues);
+    if (!JS_WrapValue(cx, &value) ||
+        !JS_DefineElement(cx, values, index, value, JSPROP_ENUMERATE)) {
+      MOZ_ASSERT(JS_IsExceptionPending(cx));
+      JS::Rooted<JS::Value> exn(cx);
+      jsapi.StealException(&exn);
+      mPromise->MaybeReject(cx, exn);
     }
 
     --mCountdown;
diff --git a/dom/tests/mochitest/general/test_interfaces.html b/dom/tests/mochitest/general/test_interfaces.html
index 1854866672..efa51198aa 100644
--- a/dom/tests/mochitest/general/test_interfaces.html
+++ b/dom/tests/mochitest/general/test_interfaces.html
@@ -834,7 +834,7 @@ var interfaceNamesInGlobalScope =
 // IMPORTANT: Do not change this list without review from a DOM peer!
     "mozRTCSessionDescription",
 // IMPORTANT: Do not change this list without review from a DOM peer!
-    "MozSettingsEvent",
+    {name: "MozSettingsEvent", permission: ["settings-api-read"]},
 // IMPORTANT: Do not change this list without review from a DOM peer!
     {name: "MozSettingsTransactionEvent", permission: ["settings-api-read"]},
 // IMPORTANT: Do not change this list without review from a DOM peer!
diff --git a/dom/webidl/CustomEvent.webidl b/dom/webidl/CustomEvent.webidl
index 180159b33a..299a41ec09 100644
--- a/dom/webidl/CustomEvent.webidl
+++ b/dom/webidl/CustomEvent.webidl
@@ -10,7 +10,8 @@
  * liability, trademark and document use rules apply.
  */
 
-[Constructor(DOMString type, optional CustomEventInit eventInitDict)]
+[Constructor(DOMString type, optional CustomEventInit eventInitDict),
+ Exposed=(Window, Worker)]
 interface CustomEvent : Event
 {
   readonly attribute any detail;
diff --git a/dom/webidl/KeyframeEffect.webidl b/dom/webidl/KeyframeEffect.webidl
index 2d748b21fa..47f3b351f0 100644
--- a/dom/webidl/KeyframeEffect.webidl
+++ b/dom/webidl/KeyframeEffect.webidl
@@ -46,14 +46,22 @@ interface KeyframeEffectReadOnly : AnimationEffectReadOnly {
 };
 
 // Non-standard extensions
-dictionary AnimationPropertyState {
-  DOMString property;
-  boolean runningOnCompositor;
-  DOMString? warning;
+dictionary AnimationPropertyValueDetails {
+  required double             offset;
+  required DOMString          value;
+           DOMString          easing;
+  required CompositeOperation composite;
+};
+
+dictionary AnimationPropertyDetails {
+  required DOMString                               property;
+  required boolean                                 runningOnCompositor;
+           DOMString                               warning;
+  required sequence<AnimationPropertyValueDetails> values;
 };
 
 partial interface KeyframeEffectReadOnly {
-  [ChromeOnly] sequence<AnimationPropertyState> getPropertyState();
+  [ChromeOnly, Throws] sequence<AnimationPropertyDetails> getProperties();
 };
 
 [Func="nsDocument::IsWebAnimationsEnabled",
diff --git a/dom/webidl/MozSettingsEvent.webidl b/dom/webidl/MozSettingsEvent.webidl
index 7f047f16d0..ba043736ad 100644
--- a/dom/webidl/MozSettingsEvent.webidl
+++ b/dom/webidl/MozSettingsEvent.webidl
@@ -4,7 +4,8 @@
  * You can obtain one at http://mozilla.org/MPL/2.0/.
  */
 
-[Constructor(DOMString type, optional MozSettingsEventInit eventInitDict)]
+[Constructor(DOMString type, optional MozSettingsEventInit eventInitDict),
+ CheckAnyPermissions="settings-api-read settings-api-write"]
 interface MozSettingsEvent : Event
 {
   readonly attribute DOMString? settingName;
diff --git a/dom/webidl/Navigator.webidl b/dom/webidl/Navigator.webidl
index 2a856a3bdb..dbbb7c31d1 100644
--- a/dom/webidl/Navigator.webidl
+++ b/dom/webidl/Navigator.webidl
@@ -43,7 +43,7 @@ interface NavigatorID {
   readonly attribute DOMString appVersion;
   [Constant, Cached]
   readonly attribute DOMString platform;
-  [Pure, Cached, Throws=Workers]
+  [Pure, Cached, Throws]
   readonly attribute DOMString userAgent;
   [Constant, Cached]
   readonly attribute DOMString product; // constant "Gecko"
diff --git a/dom/webidl/WorkerDebuggerGlobalScope.webidl b/dom/webidl/WorkerDebuggerGlobalScope.webidl
index 06d07690ab..70e477ca68 100644
--- a/dom/webidl/WorkerDebuggerGlobalScope.webidl
+++ b/dom/webidl/WorkerDebuggerGlobalScope.webidl
@@ -5,6 +5,7 @@
 
 [Global=(WorkerDebugger), Exposed=WorkerDebugger]
 interface WorkerDebuggerGlobalScope : EventTarget {
+  [Throws]
   readonly attribute object global;
 
   object createSandbox(DOMString name, object prototype);
diff --git a/dom/workers/FileReaderSync.cpp b/dom/workers/FileReaderSync.cpp
index 4620544e48..57f5852f6a 100644
--- a/dom/workers/FileReaderSync.cpp
+++ b/dom/workers/FileReaderSync.cpp
@@ -27,7 +27,6 @@
 
 #include "RuntimeService.h"
 
-USING_WORKERS_NAMESPACE
 using namespace mozilla;
 using namespace mozilla::dom;
 using mozilla::dom::Optional;
@@ -47,7 +46,7 @@ FileReaderSync::WrapObject(JSContext* aCx,
                            JS::Handle<JSObject*> aGivenProto,
                            JS::MutableHandle<JSObject*> aReflector)
 {
-  return FileReaderSyncBinding_workers::Wrap(aCx, this, aGivenProto, aReflector);
+  return FileReaderSyncBinding::Wrap(aCx, this, aGivenProto, aReflector);
 }
 
 void
diff --git a/dom/workers/FileReaderSync.h b/dom/workers/FileReaderSync.h
index 2d097233d8..db8f9d574e 100644
--- a/dom/workers/FileReaderSync.h
+++ b/dom/workers/FileReaderSync.h
@@ -4,8 +4,8 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-#ifndef mozilla_dom_workers_filereadersync_h__
-#define mozilla_dom_workers_filereadersync_h__
+#ifndef mozilla_dom_filereadersync_h__
+#define mozilla_dom_filereadersync_h__
 
 #include "Workers.h"
 
@@ -18,10 +18,6 @@ namespace dom {
 class Blob;
 class GlobalObject;
 template<typename> class Optional;
-} // namespace dom
-} // namespace mozilla
-
-BEGIN_WORKERS_NAMESPACE
 
 class FileReaderSync final
 {
@@ -51,6 +47,7 @@ public:
   void ReadAsDataURL(Blob& aBlob, nsAString& aResult, ErrorResult& aRv);
 };
 
-END_WORKERS_NAMESPACE
+} // namespace dom
+} // namespace mozilla
 
-#endif // mozilla_dom_workers_filereadersync_h__
+#endif // mozilla_dom_filereadersync_h__
diff --git a/dom/workers/ServiceWorkerEvents.cpp b/dom/workers/ServiceWorkerEvents.cpp
index a4b2b73db2..b54193bdf2 100644
--- a/dom/workers/ServiceWorkerEvents.cpp
+++ b/dom/workers/ServiceWorkerEvents.cpp
@@ -53,6 +53,47 @@
 using namespace mozilla::dom;
 using namespace mozilla::dom::workers;
 
+namespace {
+
+void
+AsyncLog(nsIInterceptedChannel *aInterceptedChannel,
+         const nsACString& aRespondWithScriptSpec,
+         uint32_t aRespondWithLineNumber, uint32_t aRespondWithColumnNumber,
+         const nsACString& aMessageName, const nsTArray<nsString>& aParams)
+{
+  MOZ_ASSERT(aInterceptedChannel);
+  nsCOMPtr<nsIConsoleReportCollector> reporter =
+    aInterceptedChannel->GetConsoleReportCollector();
+  if (reporter) {
+    reporter->AddConsoleReport(nsIScriptError::errorFlag,
+                               NS_LITERAL_CSTRING("Service Worker Interception"),
+                               nsContentUtils::eDOM_PROPERTIES,
+                               aRespondWithScriptSpec,
+                               aRespondWithLineNumber,
+                               aRespondWithColumnNumber,
+                               aMessageName, aParams);
+  }
+}
+
+template<typename... Params>
+void
+AsyncLog(nsIInterceptedChannel* aInterceptedChannel,
+         const nsACString& aRespondWithScriptSpec,
+         uint32_t aRespondWithLineNumber, uint32_t aRespondWithColumnNumber,
+         // We have to list one explicit string so that calls with an
+         // nsTArray of params won't end up in here.
+         const nsACString& aMessageName, const nsAString& aFirstParam,
+         Params&&... aParams)
+{
+  nsTArray<nsString> paramsList(sizeof...(Params) + 1);
+  StringArrayAppender::Append(paramsList, sizeof...(Params) + 1,
+                              aFirstParam, Forward<Params>(aParams)...);
+  AsyncLog(aInterceptedChannel, aRespondWithScriptSpec, aRespondWithLineNumber,
+           aRespondWithColumnNumber, aMessageName, paramsList);
+}
+
+} // anonymous namespace
+
 BEGIN_WORKERS_NAMESPACE
 
 CancelChannelRunnable::CancelChannelRunnable(nsMainThreadPtrHandle<nsIInterceptedChannel>& aChannel,
@@ -112,43 +153,6 @@ FetchEvent::Constructor(const GlobalObject& aGlobal,
 
 namespace {
 
-void
-AsyncLog(nsIInterceptedChannel *aInterceptedChannel,
-         const nsACString& aRespondWithScriptSpec,
-         uint32_t aRespondWithLineNumber, uint32_t aRespondWithColumnNumber,
-         const nsACString& aMessageName, const nsTArray<nsString>& aParams)
-{
-  MOZ_ASSERT(aInterceptedChannel);
-  nsCOMPtr<nsIConsoleReportCollector> reporter =
-    aInterceptedChannel->GetConsoleReportCollector();
-  if (reporter) {
-    reporter->AddConsoleReport(nsIScriptError::errorFlag,
-                               NS_LITERAL_CSTRING("Service Worker Interception"),
-                               nsContentUtils::eDOM_PROPERTIES,
-                               aRespondWithScriptSpec,
-                               aRespondWithLineNumber,
-                               aRespondWithColumnNumber,
-                               aMessageName, aParams);
-  }
-}
-
-template<typename... Params>
-void
-AsyncLog(nsIInterceptedChannel* aInterceptedChannel,
-         const nsACString& aRespondWithScriptSpec,
-         uint32_t aRespondWithLineNumber, uint32_t aRespondWithColumnNumber,
-         // We have to list one explicit string so that calls with an
-         // nsTArray of params won't end up in here.
-         const nsACString& aMessageName, const nsAString& aFirstParam,
-         Params&&... aParams)
-{
-  nsTArray<nsString> paramsList(sizeof...(Params) + 1);
-  StringArrayAppender::Append(paramsList, sizeof...(Params) + 1,
-                              aFirstParam, Forward<Params>(aParams)...);
-  AsyncLog(aInterceptedChannel, aRespondWithScriptSpec, aRespondWithLineNumber,
-           aRespondWithColumnNumber, aMessageName, paramsList);
-}
-
 class FinishResponse final : public nsRunnable
 {
   nsMainThreadPtrHandle<nsIInterceptedChannel> mChannel;
diff --git a/dom/workers/Location.cpp b/dom/workers/WorkerLocation.cpp
similarity index 83%
rename from dom/workers/Location.cpp
rename to dom/workers/WorkerLocation.cpp
index 30e8a2f295..469bf84bfd 100644
--- a/dom/workers/Location.cpp
+++ b/dom/workers/WorkerLocation.cpp
@@ -4,11 +4,12 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-#include "Location.h"
+#include "mozilla/dom/WorkerLocation.h"
 
 #include "mozilla/dom/WorkerLocationBinding.h"
 
-BEGIN_WORKERS_NAMESPACE
+namespace mozilla {
+namespace dom {
 
 NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE_0(WorkerLocation)
 
@@ -16,7 +17,7 @@ NS_IMPL_CYCLE_COLLECTION_ROOT_NATIVE(WorkerLocation, AddRef)
 NS_IMPL_CYCLE_COLLECTION_UNROOT_NATIVE(WorkerLocation, Release)
 
 /* static */ already_AddRefed<WorkerLocation>
-WorkerLocation::Create(WorkerPrivate::LocationInfo& aInfo)
+WorkerLocation::Create(workers::WorkerPrivate::LocationInfo& aInfo)
 {
   RefPtr<WorkerLocation> location =
     new WorkerLocation(NS_ConvertUTF8toUTF16(aInfo.mHref),
@@ -35,7 +36,8 @@ WorkerLocation::Create(WorkerPrivate::LocationInfo& aInfo)
 JSObject*
 WorkerLocation::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
 {
-  return WorkerLocationBinding_workers::Wrap(aCx, this, aGivenProto);
+  return WorkerLocationBinding::Wrap(aCx, this, aGivenProto);
 }
 
-END_WORKERS_NAMESPACE
+} // namespace dom
+} // namespace mozilla
diff --git a/dom/workers/Location.h b/dom/workers/WorkerLocation.h
similarity index 91%
rename from dom/workers/Location.h
rename to dom/workers/WorkerLocation.h
index cf70001131..73137efff2 100644
--- a/dom/workers/Location.h
+++ b/dom/workers/WorkerLocation.h
@@ -4,14 +4,15 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-#ifndef mozilla_dom_workers_location_h__
-#define mozilla_dom_workers_location_h__
+#ifndef mozilla_dom_location_h__
+#define mozilla_dom_location_h__
 
 #include "Workers.h"
 #include "WorkerPrivate.h"
 #include "nsWrapperCache.h"
 
-BEGIN_WORKERS_NAMESPACE
+namespace mozilla {
+namespace dom {
 
 class WorkerLocation final : public nsWrapperCache
 {
@@ -58,7 +59,7 @@ public:
   NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_NATIVE_CLASS(WorkerLocation)
 
   static already_AddRefed<WorkerLocation>
-  Create(WorkerPrivate::LocationInfo& aInfo);
+  Create(workers::WorkerPrivate::LocationInfo& aInfo);
 
   virtual JSObject*
   WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override;
@@ -109,6 +110,7 @@ public:
   }
 };
 
-END_WORKERS_NAMESPACE
+} // namespace dom
+} // namespace mozilla
 
-#endif // mozilla_dom_workers_location_h__
+#endif // mozilla_dom_location_h__
diff --git a/dom/workers/Navigator.cpp b/dom/workers/WorkerNavigator.cpp
similarity index 98%
rename from dom/workers/Navigator.cpp
rename to dom/workers/WorkerNavigator.cpp
index 825f51ff9e..b88dcd2bcf 100644
--- a/dom/workers/Navigator.cpp
+++ b/dom/workers/WorkerNavigator.cpp
@@ -11,9 +11,9 @@
 #include "mozilla/dom/DataStoreBinding.h"
 #include "mozilla/dom/Promise.h"
 #include "mozilla/dom/PromiseWorkerProxy.h"
+#include "mozilla/dom/WorkerNavigator.h"
 #include "mozilla/dom/WorkerNavigatorBinding.h"
 
-#include "Navigator.h"
 #include "nsProxyRelease.h"
 #include "RuntimeService.h"
 
@@ -23,7 +23,8 @@
 #include "WorkerRunnable.h"
 #include "WorkerScope.h"
 
-BEGIN_WORKERS_NAMESPACE
+namespace mozilla {
+namespace dom {
 
 NS_IMPL_CYCLE_COLLECTION_WRAPPERCACHE_0(WorkerNavigator)
 
@@ -48,7 +49,7 @@ WorkerNavigator::Create(bool aOnLine)
 JSObject*
 WorkerNavigator::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
 {
-  return WorkerNavigatorBinding_workers::Wrap(aCx, this, aGivenProto);
+  return WorkerNavigatorBinding::Wrap(aCx, this, aGivenProto);
 }
 
 // A WorkerMainThreadRunnable to synchronously add DataStoreChangeEventProxy on
@@ -300,7 +301,7 @@ WorkerNavigator::GetDataStores(JSContext* aCx,
 void
 WorkerNavigator::SetLanguages(const nsTArray<nsString>& aLanguages)
 {
-  WorkerNavigatorBinding_workers::ClearCachedLanguagesValue(this);
+  WorkerNavigatorBinding::ClearCachedLanguagesValue(this);
   mProperties.mLanguages = aLanguages;
 }
 
@@ -408,4 +409,5 @@ WorkerNavigator::HardwareConcurrency() const
   return rts->ClampedHardwareConcurrency();
 }
 
-END_WORKERS_NAMESPACE
+} // namespace dom
+} // namespace mozilla
diff --git a/dom/workers/Navigator.h b/dom/workers/WorkerNavigator.h
similarity index 91%
rename from dom/workers/Navigator.h
rename to dom/workers/WorkerNavigator.h
index c4bdb6271d..b0ba074550 100644
--- a/dom/workers/Navigator.h
+++ b/dom/workers/WorkerNavigator.h
@@ -4,8 +4,8 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-#ifndef mozilla_dom_workers_navigator_h__
-#define mozilla_dom_workers_navigator_h__
+#ifndef mozilla_dom_workernavigator_h__
+#define mozilla_dom_workernavigator_h__
 
 #include "Workers.h"
 #include "RuntimeService.h"
@@ -19,14 +19,10 @@
 namespace mozilla {
 namespace dom {
 class Promise;
-} // namespace dom
-} // namespace mozilla
-
-BEGIN_WORKERS_NAMESPACE
 
 class WorkerNavigator final : public nsWrapperCache
 {
-  typedef struct RuntimeService::NavigatorProperties NavigatorProperties;
+  typedef struct workers::RuntimeService::NavigatorProperties NavigatorProperties;
 
   NavigatorProperties mProperties;
   bool mOnline;
@@ -116,6 +112,7 @@ public:
   uint64_t HardwareConcurrency() const;
 };
 
-END_WORKERS_NAMESPACE
+} // namespace dom
+} // namespace mozilla
 
-#endif // mozilla_dom_workers_navigator_h__
+#endif // mozilla_dom_workernavigator_h__
diff --git a/dom/workers/WorkerScope.cpp b/dom/workers/WorkerScope.cpp
index 8c98f3cc81..6b14cac308 100644
--- a/dom/workers/WorkerScope.cpp
+++ b/dom/workers/WorkerScope.cpp
@@ -21,6 +21,8 @@
 #include "mozilla/dom/SharedWorkerGlobalScopeBinding.h"
 #include "mozilla/dom/WorkerDebuggerGlobalScopeBinding.h"
 #include "mozilla/dom/WorkerGlobalScopeBinding.h"
+#include "mozilla/dom/WorkerLocation.h"
+#include "mozilla/dom/WorkerNavigator.h"
 #include "mozilla/dom/cache/CacheStorage.h"
 #include "mozilla/Services.h"
 #include "nsServiceManagerUtils.h"
@@ -32,8 +34,6 @@
 #include <android/log.h>
 #endif
 
-#include "Location.h"
-#include "Navigator.h"
 #include "Principal.h"
 #include "RuntimeService.h"
 #include "ScriptLoader.h"
@@ -696,9 +696,15 @@ WorkerDebuggerGlobalScope::WrapGlobalObject(JSContext* aCx,
 
 void
 WorkerDebuggerGlobalScope::GetGlobal(JSContext* aCx,
-                                     JS::MutableHandle<JSObject*> aGlobal)
+                                     JS::MutableHandle<JSObject*> aGlobal,
+                                     ErrorResult& aRv)
 {
-  aGlobal.set(mWorkerPrivate->GetOrCreateGlobalScope(aCx)->GetWrapper());
+  WorkerGlobalScope* scope = mWorkerPrivate->GetOrCreateGlobalScope(aCx);
+  if (!scope) {
+    aRv.Throw(NS_ERROR_FAILURE);
+  }
+
+  aGlobal.set(scope->GetWrapper());
 }
 
 class WorkerDebuggerSandboxPrivate : public nsIGlobalObject,
@@ -931,7 +937,10 @@ void
 WorkerDebuggerGlobalScope::Dump(JSContext* aCx,
                                 const Optional<nsAString>& aString) const
 {
-  return mWorkerPrivate->GetOrCreateGlobalScope(aCx)->Dump(aString);
+  WorkerGlobalScope* scope = mWorkerPrivate->GetOrCreateGlobalScope(aCx);
+  if (scope) {
+    scope->Dump(aString);
+  }
 }
 
 nsIGlobalObject*
diff --git a/dom/workers/WorkerScope.h b/dom/workers/WorkerScope.h
index 50de58e397..4ba8c06cc3 100644
--- a/dom/workers/WorkerScope.h
+++ b/dom/workers/WorkerScope.h
@@ -23,6 +23,8 @@ class IDBFactory;
 class Promise;
 class RequestOrUSVString;
 class ServiceWorkerRegistrationWorkerThread;
+class WorkerLocation;
+class WorkerNavigator;
 
 namespace cache {
 
@@ -36,8 +38,6 @@ BEGIN_WORKERS_NAMESPACE
 
 class ServiceWorkerClients;
 class WorkerPrivate;
-class WorkerLocation;
-class WorkerNavigator;
 class Performance;
 
 class WorkerGlobalScope : public DOMEventTargetHelper,
@@ -297,7 +297,8 @@ public:
   }
 
   void
-  GetGlobal(JSContext* aCx, JS::MutableHandle<JSObject*> aGlobal);
+  GetGlobal(JSContext* aCx, JS::MutableHandle<JSObject*> aGlobal,
+            ErrorResult& aRv);
 
   void
   CreateSandbox(JSContext* aCx, const nsAString& aName,
diff --git a/dom/workers/moz.build b/dom/workers/moz.build
index 9bbd500682..bd2a40d7f9 100644
--- a/dom/workers/moz.build
+++ b/dom/workers/moz.build
@@ -6,12 +6,15 @@
 
 # Public stuff.
 EXPORTS.mozilla.dom += [
+    'FileReaderSync.h',
     'ServiceWorkerCommon.h',
     'ServiceWorkerContainer.h',
     'ServiceWorkerEvents.h',
     'ServiceWorkerMessageEvent.h',
     'ServiceWorkerRegistrar.h',
     'ServiceWorkerRegistration.h',
+    'WorkerLocation.h',
+    'WorkerNavigator.h',
     'WorkerPrefs.h',
     'WorkerPrivate.h',
     'WorkerRunnable.h',
@@ -29,9 +32,6 @@ EXPORTS.mozilla.dom.workers += [
 EXPORTS.mozilla.dom.workers.bindings += [
     'DataStore.h',
     'DataStoreCursor.h',
-    'FileReaderSync.h',
-    'Location.h',
-    'Navigator.h',
     'Performance.h',
     'ServiceWorker.h',
     'ServiceWorkerClient.h',
@@ -56,8 +56,6 @@ UNIFIED_SOURCES += [
     'DataStore.cpp',
     'DataStoreCursor.cpp',
     'FileReaderSync.cpp',
-    'Location.cpp',
-    'Navigator.cpp',
     'Performance.cpp',
     'Principal.cpp',
     'RegisterBindings.cpp',
@@ -81,6 +79,8 @@ UNIFIED_SOURCES += [
     'SharedWorker.cpp',
     'URL.cpp',
     'WorkerDebuggerManager.cpp',
+    'WorkerLocation.cpp',
+    'WorkerNavigator.cpp',
     'WorkerPrivate.cpp',
     'WorkerRunnable.cpp',
     'WorkerScope.cpp',
diff --git a/dom/workers/test/serviceworkers/test_serviceworker_interfaces.js b/dom/workers/test/serviceworkers/test_serviceworker_interfaces.js
index ec71a93baf..12ffa42e0b 100644
--- a/dom/workers/test/serviceworkers/test_serviceworker_interfaces.js
+++ b/dom/workers/test/serviceworkers/test_serviceworker_interfaces.js
@@ -88,6 +88,8 @@ var interfaceNamesInGlobalScope =
     "Client",
 // IMPORTANT: Do not change this list without review from a DOM peer!
     "Clients",
+// IMPORTANT: Do not change this list without review from a DOM peer!
+    "CustomEvent",
 // IMPORTANT: Do not change this list without review from a DOM peer!
     { name: "DataStore", b2g: true },
 // IMPORTANT: Do not change this list without review from a DOM peer!
diff --git a/dom/workers/test/test_worker_interfaces.js b/dom/workers/test/test_worker_interfaces.js
index b3892dd2b8..0adc1ccccf 100644
--- a/dom/workers/test/test_worker_interfaces.js
+++ b/dom/workers/test/test_worker_interfaces.js
@@ -84,6 +84,8 @@ var interfaceNamesInGlobalScope =
     "Cache",
 // IMPORTANT: Do not change this list without review from a DOM peer!
     "CacheStorage",
+// IMPORTANT: Do not change this list without review from a DOM peer!
+    "CustomEvent",
 // IMPORTANT: Do not change this list without review from a DOM peer!
     "DedicatedWorkerGlobalScope",
 // IMPORTANT: Do not change this list without review from a DOM peer!
diff --git a/layout/generic/nsBRFrame.cpp b/layout/generic/nsBRFrame.cpp
index b4695ef28e..2d7ec6487e 100644
--- a/layout/generic/nsBRFrame.cpp
+++ b/layout/generic/nsBRFrame.cpp
@@ -266,6 +266,13 @@ BRFrame::AccessibleType()
     return a11y::eNoType;
   }
 
+  // Trailing HTML br element don't play any difference. We don't need to expose
+  // it to AT (see bug https://bugzilla.mozilla.org/show_bug.cgi?id=899433#c16
+  // for details).
+  if (!mContent->GetNextSibling() && !GetNextSibling()) {
+    return a11y::eNoType;
+  }
+
   return a11y::eHTMLBRType;
 }
 #endif
diff --git a/layout/style/AnimationCollection.cpp b/layout/style/AnimationCollection.cpp
index 90d6ec28b2..f7826f5ed3 100644
--- a/layout/style/AnimationCollection.cpp
+++ b/layout/style/AnimationCollection.cpp
@@ -63,18 +63,18 @@ template <class AnimationType>
 AnimationCollection<AnimationType>::GetAnimationCollection(
   const nsIFrame* aFrame)
 {
-  Maybe<Pair<dom::Element*, CSSPseudoElementType>> pseudoElement =
+  Maybe<NonOwningAnimationTarget> pseudoElement =
     EffectCompositor::GetAnimationElementAndPseudoForFrame(aFrame);
   if (!pseudoElement) {
     return nullptr;
   }
 
-  if (!pseudoElement->first()->MayHaveAnimations()) {
+  if (!pseudoElement->mElement->MayHaveAnimations()) {
     return nullptr;
   }
 
-  return GetAnimationCollection(pseudoElement->first(),
-                                pseudoElement->second());
+  return GetAnimationCollection(pseudoElement->mElement,
+                                pseudoElement->mPseudoType);
 }
 
 template <class AnimationType>
diff --git a/modules/libjar/test/unit/test_jarchannel.js b/modules/libjar/test/unit/test_jarchannel.js
index 530ac65f45..49421b14c2 100644
--- a/modules/libjar/test/unit/test_jarchannel.js
+++ b/modules/libjar/test/unit/test_jarchannel.js
@@ -310,4 +310,6 @@ if (inChild) {
     });
 } // if inChild
 
-function run_test() run_next_test();
+function run_test() {
+  return run_next_test();
+}
diff --git a/netwerk/test/browser/browser_NetUtil.js b/netwerk/test/browser/browser_NetUtil.js
index 974a7e1feb..a6c4f2bcd6 100644
--- a/netwerk/test/browser/browser_NetUtil.js
+++ b/netwerk/test/browser/browser_NetUtil.js
@@ -42,7 +42,7 @@ function test_asyncFetchBadCert() {
     channel.notificationCallbacks = {
       QueryInterface: XPCOMUtils.generateQI([Ci.nsIProgressEventSink,
                                              Ci.nsIInterfaceRequestor]),
-      getInterface: function (aIID) this.QueryInterface(aIID),
+      getInterface: function (aIID) { return this.QueryInterface(aIID); },
       onProgress: function () {},
       onStatus: function () {}
     };
diff --git a/netwerk/test/httpserver/test/test_registerdirectory.js b/netwerk/test/httpserver/test/test_registerdirectory.js
index 3894413068..fbb41293e9 100644
--- a/netwerk/test/httpserver/test/test_registerdirectory.js
+++ b/netwerk/test/httpserver/test/test_registerdirectory.js
@@ -45,7 +45,7 @@ function checkFile(ch, cx, status, data)
   actualFile.append("test_registerdirectory.js");
   do_check_eq(ch.getResponseHeader("Content-Length"),
               actualFile.fileSize.toString());
-  do_check_eq(data.map(function(v) String.fromCharCode(v)).join(""),
+  do_check_eq(data.map(v => String.fromCharCode(v)).join(""),
               fileContents(actualFile));
 }
 
diff --git a/netwerk/test/unit/test_bug894586.js b/netwerk/test/unit/test_bug894586.js
index 080adb0afa..26e945839b 100644
--- a/netwerk/test/unit/test_bug894586.js
+++ b/netwerk/test/unit/test_bug894586.js
@@ -18,28 +18,55 @@ function ProtocolHandler() {
 
 ProtocolHandler.prototype = {
   /** nsIProtocolHandler */
-  get scheme() "x-bug894586",
-  get defaultPort() -1,
-  get protocolFlags() Ci.nsIProtocolHandler.URI_NORELATIVE |
-                      Ci.nsIProtocolHandler.URI_NOAUTH |
-                      Ci.nsIProtocolHandler.URI_IS_UI_RESOURCE |
-                      Ci.nsIProtocolHandler.URI_IS_LOCAL_RESOURCE |
-                      Ci.nsIProtocolHandler.URI_NON_PERSISTABLE |
-                      Ci.nsIProtocolHandler.URI_SYNC_LOAD_IS_OK,
-  newURI: function(aSpec, aOriginCharset, aBaseURI) this.uri,
-  newChannel: function(aURI) this,
-  allowPort: function(port, scheme) port != -1,
+  get scheme() {
+    return "x-bug894586";
+  },
+  get defaultPort() {
+    return -1;
+  },
+  get protocolFlags() {
+    return Ci.nsIProtocolHandler.URI_NORELATIVE |
+           Ci.nsIProtocolHandler.URI_NOAUTH |
+           Ci.nsIProtocolHandler.URI_IS_UI_RESOURCE |
+           Ci.nsIProtocolHandler.URI_IS_LOCAL_RESOURCE |
+           Ci.nsIProtocolHandler.URI_NON_PERSISTABLE |
+           Ci.nsIProtocolHandler.URI_SYNC_LOAD_IS_OK;
+  },
+  newURI: function(aSpec, aOriginCharset, aBaseURI) {
+    return this.uri;
+  },
+  newChannel2: function(aURI, aLoadInfo) {
+    this.loadInfo = aLoadInfo;
+    return this;
+  },
+  newChannel: function(aURI) {
+    return this;
+  },
+  allowPort: function(port, scheme) {
+    return port != -1;
+  },
 
   /** nsIChannel */
-  get originalURI() this.uri,
-  get URI() this.uri,
+  get originalURI() {
+    return this.uri;
+  },
+  get URI() {
+    return this.uri;
+  },
   owner: null,
   notificationCallbacks: null,
-  get securityInfo() null,
-  get contentType() "text/css",
-  set contentType(val) void(0),
+  get securityInfo() {
+    return null;
+  },
+  get contentType() {
+    return "text/css";
+  },
+  set contentType(val) {
+  },
   contentCharset: "UTF-8",
-  get contentLength() -1,
+  get contentLength() {
+    return -1;
+  },
   set contentLength(val) {
     throw Components.Exception("Setting content length", NS_ERROR_NOT_IMPLEMENTED);
   },
@@ -78,9 +105,13 @@ ProtocolHandler.prototype = {
   },
 
   /** nsIRequest */
-  get name() this.uri.spec,
-  isPending: function() false,
-  get status() Cr.NS_OK,
+  get name() {
+    return this.uri.spec;
+  },
+  isPending: () => false,
+  get status() {
+    return Cr.NS_OK;
+  },
   cancel: function(status) {},
   loadGroup: null,
   loadFlags: Ci.nsIRequest.LOAD_NORMAL |
diff --git a/netwerk/test/unit/test_protocolproxyservice.js b/netwerk/test/unit/test_protocolproxyservice.js
index b08865ee40..da7ef7f8bb 100644
--- a/netwerk/test/unit/test_protocolproxyservice.js
+++ b/netwerk/test/unit/test_protocolproxyservice.js
@@ -51,6 +51,9 @@ TestProtocolHandler.prototype = {
     uri.spec = spec;
     return uri;
   },
+  newChannel2: function(uri, aLoadInfo) {
+    throw Components.results.NS_ERROR_NOT_IMPLEMENTED;
+  },
   newChannel: function(uri) {
     throw Components.results.NS_ERROR_NOT_IMPLEMENTED;
   },
diff --git a/parser/xml/test/unit/results.js b/parser/xml/test/unit/results.js
index 3dbaa421e5..6de6292c13 100644
--- a/parser/xml/test/unit/results.js
+++ b/parser/xml/test/unit/results.js
@@ -14,7 +14,7 @@ var vectors = [
     "sanitized": "<html><head></head><body>&amp;alert&amp;A7&amp;(1)&amp;R&amp;UA;&amp;&amp;&lt;&amp;A9&amp;11/script&amp;X&amp;&gt;</body></html>"
   },
   {
-    "data": "0?<script>Worker(\"#\").onmessage=function(_)eval(_.data)</script> :postMessage(importScripts('data:;base64,cG9zdE1lc3NhZ2UoJ2FsZXJ0KDEpJyk'))",
+    "data": "0?<script>Worker(\"#\").onmessage=message=>eval(message.data)</script> :postMessage(importScripts('data:;base64,cG9zdE1lc3NhZ2UoJ2FsZXJ0KDEpJyk'))",
     "sanitized": "<html><head></head><body>0? :postMessage(importScripts('data:;base64,cG9zdE1lc3NhZ2UoJ2FsZXJ0KDEpJyk'))</body></html>"
   },
   {
diff --git a/security/manager/ssl/tests/mochitest/browser/browser_certViewer.js b/security/manager/ssl/tests/mochitest/browser/browser_certViewer.js
index 83b0981eee..7421ae0bd2 100644
--- a/security/manager/ssl/tests/mochitest/browser/browser_certViewer.js
+++ b/security/manager/ssl/tests/mochitest/browser/browser_certViewer.js
@@ -29,8 +29,12 @@ function test() {
   ok(cert, "found a certificate to look at");
   info("looking at certificate with nickname " + cert.nickname);
   let arg = {
-    QueryInterface: function() this,
-    getISupportAtIndex: function() this.cert,
+    QueryInterface: function() {
+      return this;
+    },
+    getISupportAtIndex: function() {
+      return this.cert;
+    },
     cert: cert
   };
   gBugWindow = window.openDialog("chrome://pippki/content/certViewer.xul",
diff --git a/testing/web-platform/meta/MANIFEST.json b/testing/web-platform/meta/MANIFEST.json
index e64b1f293c..a94ece76a0 100644
--- a/testing/web-platform/meta/MANIFEST.json
+++ b/testing/web-platform/meta/MANIFEST.json
@@ -18883,6 +18883,10 @@
         "path": "web-animations/keyframe-effect/getComputedTiming.html",
         "url": "/web-animations/keyframe-effect/getComputedTiming.html"
       },
+      {
+        "path": "web-animations/keyframe-effect/keyframe-handling.html",
+        "url": "/web-animations/keyframe-effect/keyframe-handling.html"
+      },
       {
         "path": "webaudio/the-audio-api/the-audiobuffer-interface/idl-test.html",
         "url": "/webaudio/the-audio-api/the-audiobuffer-interface/idl-test.html"
diff --git a/testing/web-platform/tests/web-animations/keyframe-effect/keyframe-handling.html b/testing/web-platform/tests/web-animations/keyframe-effect/keyframe-handling.html
new file mode 100644
index 0000000000..9eac4711f1
--- /dev/null
+++ b/testing/web-platform/tests/web-animations/keyframe-effect/keyframe-handling.html
@@ -0,0 +1,76 @@
+<!DOCTYPE html>
+<meta charset=utf-8>
+<title>Keyframe handling tests</title>
+<link rel="help" href="https://w3c.github.io/web-animations/#the-effect-value-of-a-keyframe-animation-effect">
+<link rel="author" title="Brian Birtles" href="mailto:bbirtles@mozilla.com">
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../testcommon.js"></script>
+<link rel="stylesheet" href="/resources/testharness.css">
+<body>
+<div id="log"></div>
+<div id="target"></div>
+<script>
+'use strict';
+
+test(function(t) {
+  var div = createDiv(t);
+  var anim = div.animate([ { offset: 0, opacity: 0 },
+                           { offset: 0, opacity: 0.1 },
+                           { offset: 0, opacity: 0.2 },
+                           { offset: 1, opacity: 0.8 },
+                           { offset: 1, opacity: 0.9 },
+                           { offset: 1, opacity: 1 } ],
+                         { duration: 1000,
+                           easing: 'cubic-bezier(0.5, -0.5, 0.5, 1.5)' });
+  assert_equals(getComputedStyle(div).opacity, '0.2',
+                'When progress is zero the last keyframe with offset 0 should'
+                + ' be used');
+  // http://cubic-bezier.com/#.5,-0.5,.5,1.5
+  // At t=0.15, the progress should be negative
+  anim.currentTime = 150;
+  assert_equals(getComputedStyle(div).opacity, '0',
+                'When progress is negative, the first keyframe with a 0 offset'
+                + ' should be used');
+  // At t=0.71, the progress should be just less than 1
+  anim.currentTime = 710;
+  assert_approx_equals(parseFloat(getComputedStyle(div).opacity), 0.8, 0.01,
+                'When progress is just less than 1, the first keyframe with an'
+                + ' offset of 1 should be used as the interval endpoint');
+  // At t=0.85, the progress should be > 1
+  anim.currentTime = 850;
+  assert_equals(getComputedStyle(div).opacity, '1',
+                'When progress is greater than 1.0, the last keyframe with a 1'
+                + ' offset should be used');
+  anim.finish();
+  assert_equals(getComputedStyle(div).opacity, '1',
+                'When progress is equal to 1.0, the last keyframe with a 1'
+                + ' offset should be used');
+}, 'Overlapping keyframes at 0 and 1 use the appropriate value when the'
+   + ' progress is outside the range [0, 1]');
+
+test(function(t) {
+  var div = createDiv(t);
+  var anim = div.animate([ { offset: 0, opacity: 0 },
+                           { offset: 0.5, opacity: 0.3 },
+                           { offset: 0.5, opacity: 0.5 },
+                           { offset: 0.5, opacity: 0.7 },
+                           { offset: 1, opacity: 1 } ], 1000);
+  anim.currentTime = 250;
+  assert_equals(getComputedStyle(div).opacity, '0.15',
+                'Before the overlap point, the first keyframe from the'
+                + ' overlap point should be used as interval endpoint');
+  anim.currentTime = 500;
+  assert_equals(getComputedStyle(div).opacity, '0.7',
+                'At the overlap point, the last keyframe from the'
+                + ' overlap point should be used as interval startpoint');
+  anim.currentTime = 750;
+  assert_equals(getComputedStyle(div).opacity, '0.85',
+                'After the overlap point, the last keyframe from the'
+                + ' overlap point should be used as interval startpoint');
+}, 'Overlapping keyframes between 0 and 1 use the appropriate value on each'
+   + ' side of the overlap point');
+
+done();
+</script>
+</body>
diff --git a/tools/jprof/split-profile.py b/tools/jprof/split-profile.py
index c9f1b43004..89454d3eb9 100755
--- a/tools/jprof/split-profile.py
+++ b/tools/jprof/split-profile.py
@@ -93,7 +93,14 @@ def generate_profile(options, destfile):
     args = [jprof] + options + passthrough
     print "Generating {0}".format(destfile)
     destio = open(destfile, "w")
-    process = subprocess.Popen(args, stdout=destio)
+    # jprof expects the "jprof-map" file to be in its current working directory
+    cwd = None
+    for option in passthrough:
+        if option.find("jprof-log"):
+            cwd = os.path.dirname(option)
+    if cwd is None:
+        raise StandardError("no jprof-log option given")
+    process = subprocess.Popen(args, stdout=destio, cwd=cwd)
     process.wait()
     destio.close()
     if process.returncode != 0:
diff --git a/widget/tests/bug586713_window.xul b/widget/tests/bug586713_window.xul
index a50996128c..78397afad1 100644
--- a/widget/tests/bug586713_window.xul
+++ b/widget/tests/bug586713_window.xul
@@ -44,7 +44,7 @@
 
     function onLoad() {
       foo();
-      setTimeout(function() foo(), 0);
+      setTimeout(() => foo(), 0);
     }
   ]]></script>
 </window>
diff --git a/widget/tests/test_bug760802.xul b/widget/tests/test_bug760802.xul
index 0a5fc5fe67..c5de5936c6 100644
--- a/widget/tests/test_bug760802.xul
+++ b/widget/tests/test_bug760802.xul
@@ -51,7 +51,9 @@ function shouldThrowException(fun, exception) {
             e.result === exception)
   }
 }
-function doesntThrowException(fun) !shouldThrowException(fun)
+function doesntThrowException(fun) {
+  return !shouldThrowException(fun);
+}
 
 var baseWindow = getBaseWindowInterface(this);
 var nativeHandle = baseWindow.nativeHandle;
diff --git a/widget/tests/test_taskbar_progress.xul b/widget/tests/test_taskbar_progress.xul
index 56f8005ce0..b08e9803d9 100644
--- a/widget/tests/test_taskbar_progress.xul
+++ b/widget/tests/test_taskbar_progress.xul
@@ -67,7 +67,9 @@
         }
       }
 
-      function doesntThrow(s,c,m) !shouldThrow(s,c,m)
+      function doesntThrow(s,c,m) {
+        return !shouldThrow(s,c,m);
+      }
 
       ok(doesntThrow(TP.STATE_NO_PROGRESS, 0, 0), "No progress state can be set");
       ok(doesntThrow(TP.STATE_INDETERMINATE, 0, 0), "Indeterminate state can be set");
diff --git a/xpcom/tests/unit/test_symlinks.js b/xpcom/tests/unit/test_symlinks.js
index adc5afeb3d..865639dd78 100644
--- a/xpcom/tests/unit/test_symlinks.js
+++ b/xpcom/tests/unit/test_symlinks.js
@@ -109,7 +109,9 @@ function setupTestDir(testDir, relative) {
 }
 
 function createSpaces(dirs, files, links) {
-  function longest(a, b) a.length > b.length ? a : b;
+  function longest(a, b) {
+    return a.length > b.length ? a : b;
+  }
   return dirs.concat(files, links).reduce(longest, "").replace(/./g, " ");
 }