diff --git a/dom/base/nsDocument.cpp b/dom/base/nsDocument.cpp
index 012d68455c..44c8699e61 100644
--- a/dom/base/nsDocument.cpp
+++ b/dom/base/nsDocument.cpp
@@ -82,6 +82,7 @@
 #include "nsIRefreshURI.h"
 #include "nsIWebNavigation.h"
 #include "nsIScriptError.h"
+#include "nsISimpleEnumerator.h"
 #include "nsStyleSheetService.h"
 
 #include "nsNetUtil.h"     // for NS_NewURI
@@ -6739,8 +6740,17 @@ nsIDocument::ImportNode(nsINode& aNode, bool aDeep, ErrorResult& rv) const
   nsINode* imported = &aNode;
 
   switch (imported->NodeType()) {
-    case nsIDOMNode::ATTRIBUTE_NODE:
+    case nsIDOMNode::DOCUMENT_NODE:
+    {
+      break;
+    }
     case nsIDOMNode::DOCUMENT_FRAGMENT_NODE:
+    {
+      if (ShadowRoot::FromNode(imported)) {
+        break;
+      }
+    }
+    case nsIDOMNode::ATTRIBUTE_NODE:
     case nsIDOMNode::ELEMENT_NODE:
     case nsIDOMNode::PROCESSING_INSTRUCTION_NODE:
     case nsIDOMNode::TEXT_NODE:
@@ -6760,11 +6770,10 @@ nsIDocument::ImportNode(nsINode& aNode, bool aDeep, ErrorResult& rv) const
     default:
     {
       NS_WARNING("Don't know how to clone this nodetype for importNode.");
-
-      rv.Throw(NS_ERROR_DOM_NOT_SUPPORTED_ERR);
     }
   }
 
+  rv.Throw(NS_ERROR_DOM_NOT_SUPPORTED_ERR);
   return nullptr;
 }
 
@@ -7767,6 +7776,12 @@ nsIDocument::AdoptNode(nsINode& aAdoptedNode, ErrorResult& rv)
       break;
     }
     case nsIDOMNode::DOCUMENT_FRAGMENT_NODE:
+    {
+      if (ShadowRoot::FromNode(adoptedNode)) {
+        rv.Throw(NS_ERROR_DOM_HIERARCHY_REQUEST_ERR);
+        return nullptr;
+      }
+    }
     case nsIDOMNode::ELEMENT_NODE:
     case nsIDOMNode::PROCESSING_INSTRUCTION_NODE:
     case nsIDOMNode::TEXT_NODE:
diff --git a/dom/base/nsGlobalWindow.cpp b/dom/base/nsGlobalWindow.cpp
index 550c29fcaf..bd95868bcd 100644
--- a/dom/base/nsGlobalWindow.cpp
+++ b/dom/base/nsGlobalWindow.cpp
@@ -409,18 +409,6 @@ nsGlobalWindow::DOMMinTimeoutValue() const {
   }                                                                           \
   PR_END_MACRO
 
-#define FORWARD_TO_INNER_OR_THROW(method, args, errorresult, err_rval)        \
-  PR_BEGIN_MACRO                                                              \
-  if (IsOuterWindow()) {                                                      \
-    if (!mInnerWindow) {                                                      \
-      NS_WARNING("No inner window available!");                               \
-      errorresult.Throw(NS_ERROR_NOT_INITIALIZED);                            \
-      return err_rval;                                                        \
-    }                                                                         \
-    return GetCurrentInnerWindowInternal()->method args;                      \
-  }                                                                           \
-  PR_END_MACRO
-
 #define FORWARD_TO_INNER_MODAL_CONTENT_WINDOW(method, args, err_rval)         \
   PR_BEGIN_MACRO                                                              \
   if (IsOuterWindow()) {                                                      \
@@ -3583,7 +3571,7 @@ nsGlobalWindow::GetSelf(nsIDOMWindow** aWindow)
 Navigator*
 nsGlobalWindow::GetNavigator(ErrorResult& aError)
 {
-  FORWARD_TO_INNER_OR_THROW(GetNavigator, (aError), aError, nullptr);
+  MOZ_RELEASE_ASSERT(IsInnerWindow());
 
   if (!mNavigator) {
     mNavigator = new Navigator(this);
@@ -3595,6 +3583,8 @@ nsGlobalWindow::GetNavigator(ErrorResult& aError)
 NS_IMETHODIMP
 nsGlobalWindow::GetNavigator(nsIDOMNavigator** aNavigator)
 {
+  FORWARD_TO_INNER(GetNavigator, (aNavigator), NS_ERROR_UNEXPECTED);
+
   ErrorResult rv;
   nsCOMPtr<nsIDOMNavigator> navigator = GetNavigator(rv);
   navigator.forget(aNavigator);
@@ -3605,7 +3595,7 @@ nsGlobalWindow::GetNavigator(nsIDOMNavigator** aNavigator)
 nsScreen*
 nsGlobalWindow::GetScreen(ErrorResult& aError)
 {
-  FORWARD_TO_INNER_OR_THROW(GetScreen, (aError), aError, nullptr);
+  MOZ_RELEASE_ASSERT(IsInnerWindow());
 
   if (!mScreen) {
     mScreen = nsScreen::Create(this);
@@ -3621,6 +3611,8 @@ nsGlobalWindow::GetScreen(ErrorResult& aError)
 NS_IMETHODIMP
 nsGlobalWindow::GetScreen(nsIDOMScreen** aScreen)
 {
+  FORWARD_TO_INNER(GetScreen, (aScreen), NS_ERROR_UNEXPECTED);
+
   ErrorResult rv;
   nsRefPtr<nsScreen> screen = GetScreen(rv);
   screen.forget(aScreen);
@@ -3631,7 +3623,7 @@ nsGlobalWindow::GetScreen(nsIDOMScreen** aScreen)
 nsHistory*
 nsGlobalWindow::GetHistory(ErrorResult& aError)
 {
-  FORWARD_TO_INNER_OR_THROW(GetHistory, (aError), aError, nullptr);
+  MOZ_RELEASE_ASSERT(IsInnerWindow());
 
   if (!mHistory) {
     mHistory = new nsHistory(this);
@@ -3643,6 +3635,8 @@ nsGlobalWindow::GetHistory(ErrorResult& aError)
 NS_IMETHODIMP
 nsGlobalWindow::GetHistory(nsISupports** aHistory)
 {
+  FORWARD_TO_INNER(GetHistory, (aHistory), NS_ERROR_FAILURE);
+
   ErrorResult rv;
   nsCOMPtr<nsISupports> history = GetHistory(rv);
   history.forget(aHistory);
@@ -3769,7 +3763,7 @@ nsPIDOMWindow::RefreshMediaElements()
 SpeechSynthesis*
 nsGlobalWindow::GetSpeechSynthesis(ErrorResult& aError)
 {
-  FORWARD_TO_INNER_OR_THROW(GetSpeechSynthesis, (aError), aError, nullptr);
+  MOZ_RELEASE_ASSERT(IsInnerWindow());
 
   if (!mSpeechSynthesis) {
     mSpeechSynthesis = new SpeechSynthesis(this);
@@ -3999,6 +3993,8 @@ nsGlobalWindow::GetContent(nsIDOMWindow** aContent)
 MozSelfSupport*
 nsGlobalWindow::GetMozSelfSupport(ErrorResult& aError)
 {
+  MOZ_ASSERT(IsInnerWindow());
+
   if (mMozSelfSupport) {
     return mMozSelfSupport;
   }
@@ -4047,7 +4043,7 @@ nsGlobalWindow::GetPrompter(nsIPrompt** aPrompt)
 BarProp*
 nsGlobalWindow::GetMenubar(ErrorResult& aError)
 {
-  FORWARD_TO_INNER_OR_THROW(GetMenubar, (aError), aError, nullptr);
+  MOZ_RELEASE_ASSERT(IsInnerWindow());
 
   if (!mMenubar) {
     mMenubar = new MenubarProp(this);
@@ -4059,6 +4055,8 @@ nsGlobalWindow::GetMenubar(ErrorResult& aError)
 NS_IMETHODIMP
 nsGlobalWindow::GetMenubar(nsISupports** aMenubar)
 {
+  FORWARD_TO_INNER(GetMenubar, (aMenubar), NS_ERROR_UNEXPECTED);
+
   ErrorResult rv;
   nsCOMPtr<nsISupports> menubar = GetMenubar(rv);
   menubar.forget(aMenubar);
@@ -4069,7 +4067,7 @@ nsGlobalWindow::GetMenubar(nsISupports** aMenubar)
 BarProp*
 nsGlobalWindow::GetToolbar(ErrorResult& aError)
 {
-  FORWARD_TO_INNER_OR_THROW(GetToolbar, (aError), aError, nullptr);
+  MOZ_RELEASE_ASSERT(IsInnerWindow());
 
   if (!mToolbar) {
     mToolbar = new ToolbarProp(this);
@@ -4081,6 +4079,8 @@ nsGlobalWindow::GetToolbar(ErrorResult& aError)
 NS_IMETHODIMP
 nsGlobalWindow::GetToolbar(nsISupports** aToolbar)
 {
+  FORWARD_TO_INNER(GetToolbar, (aToolbar), NS_ERROR_UNEXPECTED);
+
   ErrorResult rv;
   nsCOMPtr<nsISupports> toolbar = GetToolbar(rv);
   toolbar.forget(aToolbar);
@@ -4091,7 +4091,7 @@ nsGlobalWindow::GetToolbar(nsISupports** aToolbar)
 BarProp*
 nsGlobalWindow::GetLocationbar(ErrorResult& aError)
 {
-  FORWARD_TO_INNER_OR_THROW(GetLocationbar, (aError), aError, nullptr);
+  MOZ_RELEASE_ASSERT(IsInnerWindow());
 
   if (!mLocationbar) {
     mLocationbar = new LocationbarProp(this);
@@ -4102,6 +4102,8 @@ nsGlobalWindow::GetLocationbar(ErrorResult& aError)
 NS_IMETHODIMP
 nsGlobalWindow::GetLocationbar(nsISupports** aLocationbar)
 {
+  FORWARD_TO_INNER(GetLocationbar, (aLocationbar), NS_ERROR_UNEXPECTED);
+
   ErrorResult rv;
   nsCOMPtr<nsISupports> locationbar = GetLocationbar(rv);
   locationbar.forget(aLocationbar);
@@ -4112,7 +4114,7 @@ nsGlobalWindow::GetLocationbar(nsISupports** aLocationbar)
 BarProp*
 nsGlobalWindow::GetPersonalbar(ErrorResult& aError)
 {
-  FORWARD_TO_INNER_OR_THROW(GetPersonalbar, (aError), aError, nullptr);
+  MOZ_RELEASE_ASSERT(IsInnerWindow());
 
   if (!mPersonalbar) {
     mPersonalbar = new PersonalbarProp(this);
@@ -4123,6 +4125,8 @@ nsGlobalWindow::GetPersonalbar(ErrorResult& aError)
 NS_IMETHODIMP
 nsGlobalWindow::GetPersonalbar(nsISupports** aPersonalbar)
 {
+  FORWARD_TO_INNER(GetPersonalbar, (aPersonalbar), NS_ERROR_UNEXPECTED);
+
   ErrorResult rv;
   nsCOMPtr<nsISupports> personalbar = GetPersonalbar(rv);
   personalbar.forget(aPersonalbar);
@@ -4133,7 +4137,7 @@ nsGlobalWindow::GetPersonalbar(nsISupports** aPersonalbar)
 BarProp*
 nsGlobalWindow::GetStatusbar(ErrorResult& aError)
 {
-  FORWARD_TO_INNER_OR_THROW(GetStatusbar, (aError), aError, nullptr);
+  MOZ_RELEASE_ASSERT(IsInnerWindow());
 
   if (!mStatusbar) {
     mStatusbar = new StatusbarProp(this);
@@ -4144,6 +4148,8 @@ nsGlobalWindow::GetStatusbar(ErrorResult& aError)
 NS_IMETHODIMP
 nsGlobalWindow::GetStatusbar(nsISupports** aStatusbar)
 {
+  FORWARD_TO_INNER(GetStatusbar, (aStatusbar), NS_ERROR_UNEXPECTED);
+
   ErrorResult rv;
   nsCOMPtr<nsISupports> statusbar = GetStatusbar(rv);
   statusbar.forget(aStatusbar);
@@ -4154,7 +4160,7 @@ nsGlobalWindow::GetStatusbar(nsISupports** aStatusbar)
 BarProp*
 nsGlobalWindow::GetScrollbars(ErrorResult& aError)
 {
-  FORWARD_TO_INNER_OR_THROW(GetScrollbars, (aError), aError, nullptr);
+  MOZ_RELEASE_ASSERT(IsInnerWindow());
 
   if (!mScrollbars) {
     mScrollbars = new ScrollbarsProp(this);
@@ -4166,6 +4172,8 @@ nsGlobalWindow::GetScrollbars(ErrorResult& aError)
 NS_IMETHODIMP
 nsGlobalWindow::GetScrollbars(nsISupports** aScrollbars)
 {
+  FORWARD_TO_INNER(GetScrollbars, (aScrollbars), NS_ERROR_UNEXPECTED);
+
   ErrorResult rv;
   nsCOMPtr<nsISupports> scrollbars = GetScrollbars(rv);
   scrollbars.forget(aScrollbars);
@@ -4307,6 +4315,7 @@ void
 nsGlobalWindow::GetOwnPropertyNames(JSContext* aCx, nsTArray<nsString>& aNames,
                                     ErrorResult& aRv)
 {
+  MOZ_ASSERT(IsInnerWindow());
   // "Components" is marked as enumerable but only resolved on demand :-/.
   //aNames.AppendElement(NS_LITERAL_STRING("Components"));
 
@@ -4351,7 +4360,7 @@ nsGlobalWindow::IsShowModalDialogEnabled(JSContext*, JSObject*)
 nsIDOMOfflineResourceList*
 nsGlobalWindow::GetApplicationCache(ErrorResult& aError)
 {
-  FORWARD_TO_INNER_OR_THROW(GetApplicationCache, (aError), aError, nullptr);
+  MOZ_RELEASE_ASSERT(IsInnerWindow());
 
   if (!mApplicationCache) {
     nsCOMPtr<nsIWebNavigation> webNav(do_QueryInterface(GetDocShell()));
@@ -4383,6 +4392,8 @@ nsGlobalWindow::GetApplicationCache(ErrorResult& aError)
 NS_IMETHODIMP
 nsGlobalWindow::GetApplicationCache(nsIDOMOfflineResourceList **aApplicationCache)
 {
+  FORWARD_TO_INNER(GetApplicationCache, (aApplicationCache), NS_ERROR_UNEXPECTED);
+
   ErrorResult rv;
   nsCOMPtr<nsIDOMOfflineResourceList> applicationCache =
     GetApplicationCache(rv);
@@ -4394,7 +4405,7 @@ nsGlobalWindow::GetApplicationCache(nsIDOMOfflineResourceList **aApplicationCach
 Crypto*
 nsGlobalWindow::GetCrypto(ErrorResult& aError)
 {
-  FORWARD_TO_INNER_OR_THROW(GetCrypto, (aError), aError, nullptr);
+  MOZ_RELEASE_ASSERT(IsInnerWindow());
 
   if (!mCrypto) {
     mCrypto = new Crypto();
@@ -4406,6 +4417,8 @@ nsGlobalWindow::GetCrypto(ErrorResult& aError)
 NS_IMETHODIMP
 nsGlobalWindow::GetCrypto(nsIDOMCrypto** aCrypto)
 {
+  FORWARD_TO_INNER(GetCrypto, (aCrypto), NS_ERROR_UNEXPECTED);
+
   ErrorResult rv;
   nsCOMPtr<nsIDOMCrypto> crypto = GetCrypto(rv);
   crypto.forget(aCrypto);
@@ -5308,6 +5321,8 @@ NS_IMETHODIMP
 nsGlobalWindow::MozRequestAnimationFrame(nsIFrameRequestCallback* aCallback,
                                          int32_t *aHandle)
 {
+  FORWARD_TO_INNER(MozRequestAnimationFrame, (aCallback, aHandle), NS_ERROR_UNEXPECTED);
+
   if (!aCallback) {
     if (mDoc) {
       mDoc->WarnOnceAbout(nsIDocument::eMozBeforePaint);
@@ -5326,6 +5341,8 @@ int32_t
 nsGlobalWindow::RequestAnimationFrame(FrameRequestCallback& aCallback,
                                       ErrorResult& aError)
 {
+  MOZ_RELEASE_ASSERT(IsInnerWindow());
+
   nsIDocument::FrameRequestCallbackHolder holder(&aCallback);
   return RequestAnimationFrame(holder, aError);
 }
@@ -5334,6 +5351,7 @@ int32_t
 nsGlobalWindow::MozRequestAnimationFrame(nsIFrameRequestCallback* aCallback,
                                          ErrorResult& aError)
 {
+  MOZ_RELEASE_ASSERT(IsInnerWindow());
   nsIDocument::FrameRequestCallbackHolder holder(aCallback);
   return RequestAnimationFrame(holder, aError);
 }
@@ -5342,8 +5360,7 @@ int32_t
 nsGlobalWindow::RequestAnimationFrame(const nsIDocument::FrameRequestCallbackHolder& aCallback,
                                       ErrorResult& aError)
 {
-  FORWARD_TO_INNER_OR_THROW(RequestAnimationFrame, (aCallback, aError), aError,
-                            0);
+  MOZ_RELEASE_ASSERT(IsInnerWindow());
 
   if (!mDoc) {
     return 0;
@@ -5363,6 +5380,7 @@ nsGlobalWindow::RequestAnimationFrame(JS::Handle<JS::Value> aCallback,
                                       JSContext* cx,
                                       int32_t* aHandle)
 {
+  FORWARD_TO_INNER(RequestAnimationFrame, (aCallback, cx, aHandle), NS_ERROR_UNEXPECTED);
   if (!aCallback.isObject() || !JS::IsCallable(&aCallback.toObject())) {
     return NS_ERROR_INVALID_ARG;
   }
@@ -5380,19 +5398,21 @@ nsGlobalWindow::RequestAnimationFrame(JS::Handle<JS::Value> aCallback,
 NS_IMETHODIMP
 nsGlobalWindow::MozCancelRequestAnimationFrame(int32_t aHandle)
 {
+  FORWARD_TO_INNER(MozCancelRequestAnimationFrame, (aHandle), NS_ERROR_UNEXPECTED);
   return CancelAnimationFrame(aHandle);
 }
 
 NS_IMETHODIMP
 nsGlobalWindow::MozCancelAnimationFrame(int32_t aHandle)
 {
+  FORWARD_TO_INNER(MozCancelAnimationFrame, (aHandle), NS_ERROR_UNEXPECTED);
   return CancelAnimationFrame(aHandle);
 }
 
 void
 nsGlobalWindow::CancelAnimationFrame(int32_t aHandle, ErrorResult& aError)
 {
-  FORWARD_TO_INNER_OR_THROW(CancelAnimationFrame, (aHandle, aError), aError, );
+  MOZ_RELEASE_ASSERT(IsInnerWindow());
 
   if (!mDoc) {
     return;
@@ -5404,6 +5424,8 @@ nsGlobalWindow::CancelAnimationFrame(int32_t aHandle, ErrorResult& aError)
 NS_IMETHODIMP
 nsGlobalWindow::CancelAnimationFrame(int32_t aHandle)
 {
+  FORWARD_TO_INNER(CancelAnimationFrame, (aHandle), NS_ERROR_UNEXPECTED);
+
   ErrorResult rv;
   CancelAnimationFrame(aHandle, rv);
 
@@ -5413,7 +5435,7 @@ nsGlobalWindow::CancelAnimationFrame(int32_t aHandle)
 int64_t
 nsGlobalWindow::GetMozAnimationStartTime(ErrorResult& aError)
 {
-  FORWARD_TO_INNER_OR_THROW(GetMozAnimationStartTime, (aError), aError, 0);
+  MOZ_RELEASE_ASSERT(IsInnerWindow());
 
   if (mDoc) {
     nsIPresShell* presShell = mDoc->GetShell();
@@ -5430,6 +5452,8 @@ nsGlobalWindow::GetMozAnimationStartTime(ErrorResult& aError)
 NS_IMETHODIMP
 nsGlobalWindow::GetMozAnimationStartTime(int64_t *aTime)
 {
+  FORWARD_TO_INNER(GetMozAnimationStartTime, (aTime), NS_ERROR_UNEXPECTED);
+
   ErrorResult rv;
   *aTime = GetMozAnimationStartTime(rv);
 
@@ -7521,6 +7545,8 @@ nsGlobalWindow::MozRequestOverfill(OverfillCallback& aCallback,
 void
 nsGlobalWindow::ClearTimeout(int32_t aHandle, ErrorResult& aError)
 {
+  MOZ_RELEASE_ASSERT(IsInnerWindow());
+
   if (aHandle > 0) {
     ClearTimeoutOrInterval(aHandle, aError);
   }
@@ -7529,6 +7555,8 @@ nsGlobalWindow::ClearTimeout(int32_t aHandle, ErrorResult& aError)
 NS_IMETHODIMP
 nsGlobalWindow::ClearTimeout(int32_t aHandle)
 {
+  FORWARD_TO_INNER(ClearTimeout, (aHandle), NS_ERROR_UNEXPECTED);
+
   ErrorResult rv;
   ClearTimeout(aHandle, rv);
 
@@ -8919,12 +8947,47 @@ nsGlobalWindow::GetRealFrameElement(nsIDOMElement** aFrameElement)
   return rv.StealNSResult();
 }
 
+/* static */ bool
+nsGlobalWindow::TokenizeDialogOptions(nsAString& aToken,
+                                      nsAString::const_iterator& aIter,
+                                      nsAString::const_iterator aEnd)
+{
+  while (aIter != aEnd && nsCRT::IsAsciiSpace(*aIter)) {
+    ++aIter;
+  }
+
+  if (aIter == aEnd) {
+    return false;
+  }
+
+  if (*aIter == ';' || *aIter == ':' || *aIter == '=') {
+    aToken.Assign(*aIter);
+    ++aIter;
+    return true;
+  }
+
+  nsAString::const_iterator start = aIter;
+
+  // Skip characters until we find whitespace, ';', ':', or '='
+  while (aIter != aEnd && !nsCRT::IsAsciiSpace(*aIter) &&
+         *aIter != ';' &&
+         *aIter != ':' &&
+         *aIter != '=') {
+    ++aIter;
+  }
+
+  aToken.Assign(Substring(start, aIter));
+  return true;
+}
+
 // Helper for converting window.showModalDialog() options (list of ';'
 // separated name (:|=) value pairs) to a format that's parsable by
 // our normal window opening code.
 
+/* static */
 void
-ConvertDialogOptions(const nsAString& aOptions, nsAString& aResult)
+nsGlobalWindow::ConvertDialogOptions(const nsAString& aOptions,
+                                     nsAString& aResult)
 {
   nsAString::const_iterator end;
   aOptions.EndReading(end);
@@ -8932,68 +8995,35 @@ ConvertDialogOptions(const nsAString& aOptions, nsAString& aResult)
   nsAString::const_iterator iter;
   aOptions.BeginReading(iter);
 
-  while (iter != end) {
-    // Skip whitespace.
-    while (nsCRT::IsAsciiSpace(*iter) && iter != end) {
-      ++iter;
+  nsAutoString token;
+  nsAutoString name;
+  nsAutoString value;
+
+  while (true) {
+    if (!TokenizeDialogOptions(name, iter, end)) {
+      break;
     }
 
-    nsAString::const_iterator name_start = iter;
-
-    // Skip characters until we find whitespace, ';', ':', or '='
-    while (iter != end && !nsCRT::IsAsciiSpace(*iter) &&
-           *iter != ';' &&
-           *iter != ':' &&
-           *iter != '=') {
-      ++iter;
+    // Invalid name.
+    if (name.EqualsLiteral("=") ||
+        name.EqualsLiteral(":") ||
+        name.EqualsLiteral(";")) {
+      break;
     }
 
-    nsAString::const_iterator name_end = iter;
-
-    // Skip whitespace.
-    while (nsCRT::IsAsciiSpace(*iter) && iter != end) {
-      ++iter;
+    if (!TokenizeDialogOptions(token, iter, end)) {
+      break;
     }
 
-    if (*iter == ';') {
-      // No value found, skip the ';' and keep going.
-      ++iter;
-
+    if (!token.EqualsLiteral(":") && !token.EqualsLiteral("=")) {
       continue;
     }
 
-    nsAString::const_iterator value_start = iter;
-    nsAString::const_iterator value_end = iter;
-
-    if (*iter == ':' || *iter == '=') {
-      // We found name followed by ':' or '='. Look for a value.
-
-      iter++; // Skip the ':' or '='
-
-      // Skip whitespace.
-      while (nsCRT::IsAsciiSpace(*iter) && iter != end) {
-        ++iter;
-      }
-
-      value_start = iter;
-
-      // Skip until we find whitespace, or ';'.
-      while (iter != end && !nsCRT::IsAsciiSpace(*iter) &&
-             *iter != ';') {
-        ++iter;
-      }
-
-      value_end = iter;
-
-      // Skip whitespace.
-      while (nsCRT::IsAsciiSpace(*iter) && iter != end) {
-        ++iter;
-      }
+    // We found name followed by ':' or '='. Look for a value.
+    if (!TokenizeDialogOptions(value, iter, end)) {
+      break;
     }
 
-    const nsDependentSubstring& name = Substring(name_start, name_end);
-    const nsDependentSubstring& value = Substring(value_start, value_end);
-
     if (name.LowerCaseEqualsLiteral("center")) {
       if (value.LowerCaseEqualsLiteral("on")  ||
           value.LowerCaseEqualsLiteral("yes") ||
@@ -9034,11 +9064,11 @@ ConvertDialogOptions(const nsAString& aOptions, nsAString& aResult)
       }
     }
 
-    if (iter == end) {
+    if (iter == end ||
+        !TokenizeDialogOptions(token, iter, end) ||
+        !token.EqualsLiteral(";")) {
       break;
     }
-
-    iter++;
   }
 }
 
@@ -9620,11 +9650,10 @@ nsGlobalWindow::GetPrivateRoot()
   return static_cast<nsGlobalWindow*>(top.get());
 }
 
-
 nsLocation*
 nsGlobalWindow::GetLocation(ErrorResult& aError)
 {
-  FORWARD_TO_INNER_OR_THROW(GetLocation, (aError), aError, nullptr);
+  MOZ_RELEASE_ASSERT(IsInnerWindow());
 
   nsIDocShell *docShell = GetDocShell();
   if (!mLocation && docShell) {
@@ -9636,6 +9665,8 @@ nsGlobalWindow::GetLocation(ErrorResult& aError)
 NS_IMETHODIMP
 nsGlobalWindow::GetLocation(nsIDOMLocation ** aLocation)
 {
+  FORWARD_TO_INNER(GetLocation, (aLocation), NS_ERROR_UNEXPECTED);
+
   ErrorResult rv;
   nsCOMPtr<nsIDOMLocation> location = GetLocation(rv);
   location.forget(aLocation);
@@ -10016,7 +10047,7 @@ private:
 nsresult
 nsGlobalWindow::DispatchAsyncHashchange(nsIURI *aOldURI, nsIURI *aNewURI)
 {
-  FORWARD_TO_INNER(DispatchAsyncHashchange, (aOldURI, aNewURI), NS_OK);
+  MOZ_RELEASE_ASSERT(IsInnerWindow());
 
   // Make sure that aOldURI and aNewURI are identical up to the '#', and that
   // their hashes are different.
@@ -10046,8 +10077,9 @@ nsGlobalWindow::FireHashchange(const nsAString &aOldURL,
   MOZ_ASSERT(IsInnerWindow());
 
   // Don't do anything if the window is frozen.
-  if (IsFrozen())
+  if (IsFrozen()) {
     return NS_OK;
+  }
 
   // Get a presentation shell for use in creating the hashchange event.
   NS_ENSURE_STATE(IsCurrentInnerWindow());
@@ -10077,8 +10109,7 @@ nsGlobalWindow::FireHashchange(const nsAString &aOldURL,
 nsresult
 nsGlobalWindow::DispatchSyncPopState()
 {
-  FORWARD_TO_INNER(DispatchSyncPopState, (), NS_OK);
-
+  MOZ_RELEASE_ASSERT(IsInnerWindow());
   NS_ASSERTION(nsContentUtils::IsSafeToRunScript(),
                "Must be safe to run script here.");
 
@@ -10306,7 +10337,7 @@ nsGlobalWindow::GetComputedStyleHelper(Element& aElt,
 DOMStorage*
 nsGlobalWindow::GetSessionStorage(ErrorResult& aError)
 {
-  FORWARD_TO_INNER_OR_THROW(GetSessionStorage, (aError), aError, nullptr);
+  MOZ_RELEASE_ASSERT(IsInnerWindow());
 
   nsIPrincipal *principal = GetPrincipal();
   nsIDocShell* docShell = GetDocShell();
@@ -10385,6 +10416,8 @@ nsGlobalWindow::GetSessionStorage(ErrorResult& aError)
 NS_IMETHODIMP
 nsGlobalWindow::GetSessionStorage(nsISupports** aSessionStorage)
 {
+  FORWARD_TO_INNER(GetSessionStorage, (aSessionStorage), NS_ERROR_FAILURE);
+
   ErrorResult rv;
   nsCOMPtr<nsIDOMStorage> storage = GetSessionStorage(rv);
   storage.forget(aSessionStorage);
@@ -10395,7 +10428,7 @@ nsGlobalWindow::GetSessionStorage(nsISupports** aSessionStorage)
 DOMStorage*
 nsGlobalWindow::GetLocalStorage(ErrorResult& aError)
 {
-  FORWARD_TO_INNER_OR_THROW(GetLocalStorage, (aError), aError, nullptr);
+  MOZ_RELEASE_ASSERT(IsInnerWindow());
 
   if (!Preferences::GetBool(kStorageEnabled)) {
     return nullptr;
@@ -10451,6 +10484,7 @@ NS_IMETHODIMP
 nsGlobalWindow::GetLocalStorage(nsISupports** aLocalStorage)
 {
   NS_ENSURE_ARG(aLocalStorage);
+  FORWARD_TO_INNER(GetLocalStorage, (aLocalStorage), NS_ERROR_UNEXPECTED);
 
   ErrorResult rv;
   nsCOMPtr<nsIDOMStorage> storage = GetLocalStorage(rv);
@@ -10462,6 +10496,7 @@ nsGlobalWindow::GetLocalStorage(nsISupports** aLocalStorage)
 IDBFactory*
 nsGlobalWindow::GetIndexedDB(ErrorResult& aError)
 {
+  MOZ_RELEASE_ASSERT(IsInnerWindow());
   if (!mIndexedDB) {
     // This may keep mIndexedDB null without setting an error.
     aError = IDBFactory::CreateForWindow(this, getter_AddRefs(mIndexedDB));
@@ -10564,13 +10599,9 @@ already_AddRefed<CacheStorage>
 nsGlobalWindow::GetCaches(ErrorResult& aRv)
 {
   if (!mCacheStorage) {
-    bool forceTrustedOrigin = false;
-    if (IsOuterWindow()) {
-      forceTrustedOrigin = GetServiceWorkersTestingEnabled();
-    } else {
-      nsRefPtr<nsGlobalWindow> outer = GetOuterWindowInternal();
-      forceTrustedOrigin = outer->GetServiceWorkersTestingEnabled();
-    }
+    bool forceTrustedOrigin =
+      GetOuterWindowInternal()->GetServiceWorkersTestingEnabled();
+
     mCacheStorage = CacheStorage::CreateOnMainThread(cache::DEFAULT_NAMESPACE,
                                                      this, GetPrincipal(),
                                                      IsPrivateBrowsing(),
@@ -12409,8 +12440,7 @@ nsGlobalWindow::RunTimeout(nsTimeout *aTimeout)
 void
 nsGlobalWindow::ClearTimeoutOrInterval(int32_t aTimerID, ErrorResult& aError)
 {
-  FORWARD_TO_INNER_OR_THROW(ClearTimeoutOrInterval, (aTimerID, aError),
-                            aError, );
+  MOZ_RELEASE_ASSERT(IsInnerWindow());
 
   uint32_t public_id = (uint32_t)aTimerID;
   nsTimeout *timeout;
@@ -13654,6 +13684,8 @@ nsGlobalWindow::NotifyDefaultButtonLoaded(Element& aDefaultButton,
 NS_IMETHODIMP
 nsGlobalChromeWindow::GetMessageManager(nsIMessageBroadcaster** aManager)
 {
+  FORWARD_TO_INNER_CHROME(GetMessageManager, (aManager), NS_ERROR_UNEXPECTED);
+
   ErrorResult rv;
   NS_IF_ADDREF(*aManager = GetMessageManager(rv));
   return rv.StealNSResult();
@@ -13662,8 +13694,8 @@ nsGlobalChromeWindow::GetMessageManager(nsIMessageBroadcaster** aManager)
 nsIMessageBroadcaster*
 nsGlobalWindow::GetMessageManager(ErrorResult& aError)
 {
-  FORWARD_TO_INNER_OR_THROW(GetMessageManager, (aError), aError, nullptr);
   MOZ_ASSERT(IsChromeWindow());
+  MOZ_RELEASE_ASSERT(IsInnerWindow());
   nsGlobalChromeWindow* myself = static_cast<nsGlobalChromeWindow*>(this);
   if (!myself->mMessageManager) {
     nsCOMPtr<nsIMessageBroadcaster> globalMM =
@@ -13680,6 +13712,8 @@ NS_IMETHODIMP
 nsGlobalChromeWindow::GetGroupMessageManager(const nsAString& aGroup,
                                              nsIMessageBroadcaster** aManager)
 {
+  FORWARD_TO_INNER_CHROME(GetGroupMessageManager, (aGroup, aManager), NS_ERROR_UNEXPECTED);
+
   ErrorResult rv;
   NS_IF_ADDREF(*aManager = GetGroupMessageManager(aGroup, rv));
   return rv.StealNSResult();
@@ -13689,8 +13723,8 @@ nsIMessageBroadcaster*
 nsGlobalWindow::GetGroupMessageManager(const nsAString& aGroup,
                                        ErrorResult& aError)
 {
-  FORWARD_TO_INNER_OR_THROW(GetGroupMessageManager, (aGroup, aError), aError, nullptr);
   MOZ_ASSERT(IsChromeWindow());
+  MOZ_RELEASE_ASSERT(IsInnerWindow());
 
   nsGlobalChromeWindow* myself = static_cast<nsGlobalChromeWindow*>(this);
   nsCOMPtr<nsIMessageBroadcaster> messageManager =
@@ -13855,6 +13889,8 @@ NS_IMETHODIMP
 nsGlobalWindow::GetConsole(JSContext* aCx,
                            JS::MutableHandle<JS::Value> aConsole)
 {
+  FORWARD_TO_INNER(GetConsole, (aCx, aConsole), NS_ERROR_FAILURE);
+
   ErrorResult rv;
   nsRefPtr<Console> console = GetConsole(rv);
   if (rv.Failed()) {
@@ -13879,7 +13915,7 @@ nsGlobalWindow::SetConsole(JSContext* aCx, JS::Handle<JS::Value> aValue)
 Console*
 nsGlobalWindow::GetConsole(ErrorResult& aRv)
 {
-  FORWARD_TO_INNER_OR_THROW(GetConsole, (aRv), aRv, nullptr);
+  MOZ_RELEASE_ASSERT(IsInnerWindow());
 
   if (!mConsole) {
     mConsole = new Console(this);
@@ -13891,7 +13927,7 @@ nsGlobalWindow::GetConsole(ErrorResult& aRv)
 already_AddRefed<External>
 nsGlobalWindow::GetExternal(ErrorResult& aRv)
 {
-  FORWARD_TO_INNER_OR_THROW(GetExternal, (aRv), aRv, nullptr);
+  MOZ_RELEASE_ASSERT(IsInnerWindow());
 
 #ifdef HAVE_SIDEBAR
   if (!mExternal) {
@@ -13917,7 +13953,7 @@ void
 nsGlobalWindow::GetSidebar(OwningExternalOrWindowProxy& aResult,
                            ErrorResult& aRv)
 {
-  FORWARD_TO_INNER_OR_THROW(GetSidebar, (aResult, aRv), aRv, );
+  MOZ_RELEASE_ASSERT(IsInnerWindow());
 
 #ifdef HAVE_SIDEBAR
   // First check for a named frame named "sidebar"
diff --git a/dom/base/nsGlobalWindow.h b/dom/base/nsGlobalWindow.h
index 0ee4d9a6af..ee4350933e 100644
--- a/dom/base/nsGlobalWindow.h
+++ b/dom/base/nsGlobalWindow.h
@@ -893,6 +893,13 @@ public:
                   mozilla::ErrorResult& aRv);
   already_AddRefed<mozilla::dom::External> GetExternal(mozilla::ErrorResult& aRv);
 
+  // Exposed only for testing
+  static bool
+  TokenizeDialogOptions(nsAString& aToken, nsAString::const_iterator& aIter,
+                        nsAString::const_iterator aEnd);
+  static void
+  ConvertDialogOptions(const nsAString& aOptions, nsAString& aResult);
+
 protected:
   bool AlertOrConfirm(bool aAlert, const nsAString& aMessage,
                       mozilla::ErrorResult& aError);
@@ -1622,6 +1629,7 @@ protected:
   nsRefPtr<mozilla::dom::Navigator> mNavigator;
   nsRefPtr<nsScreen>            mScreen;
   nsRefPtr<nsDOMWindowList>     mFrames;
+  // All BarProps are inner window only.
   nsRefPtr<mozilla::dom::BarProp> mMenubar;
   nsRefPtr<mozilla::dom::BarProp> mToolbar;
   nsRefPtr<mozilla::dom::BarProp> mLocationbar;
diff --git a/dom/base/nsHistory.cpp b/dom/base/nsHistory.cpp
index 09d54d6068..837a2694f6 100644
--- a/dom/base/nsHistory.cpp
+++ b/dom/base/nsHistory.cpp
@@ -46,6 +46,7 @@ NS_INTERFACE_MAP_END
 nsHistory::nsHistory(nsPIDOMWindow* aInnerWindow)
   : mInnerWindow(do_GetWeakReference(aInnerWindow))
 {
+  MOZ_ASSERT(aInnerWindow->IsInnerWindow());
 }
 
 nsHistory::~nsHistory()
diff --git a/dom/base/nsScreen.cpp b/dom/base/nsScreen.cpp
index b1249691f2..3d7fb38b08 100644
--- a/dom/base/nsScreen.cpp
+++ b/dom/base/nsScreen.cpp
@@ -25,6 +25,7 @@ using namespace mozilla::dom;
 nsScreen::Create(nsPIDOMWindow* aWindow)
 {
   MOZ_ASSERT(aWindow);
+  MOZ_ASSERT(aWindow->IsInnerWindow());
 
   if (!aWindow->GetDocShell()) {
     return nullptr;
diff --git a/dom/base/test/gtest/TestParserDialogOptions.cpp b/dom/base/test/gtest/TestParserDialogOptions.cpp
new file mode 100644
index 0000000000..055f9ebfdf
--- /dev/null
+++ b/dom/base/test/gtest/TestParserDialogOptions.cpp
@@ -0,0 +1,138 @@
+/* -*- 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/. */
+
+#include "gtest/gtest.h"
+#include "nsGlobalWindow.h"
+
+struct dialog_test {
+  const char* input;
+  const char* output;
+};
+
+void runTokenizeTest(dialog_test& test)
+{
+  NS_ConvertUTF8toUTF16 input(test.input);
+
+  nsAString::const_iterator end;
+  input.EndReading(end);
+
+  nsAString::const_iterator iter;
+  input.BeginReading(iter);
+
+  nsAutoString result;
+  nsAutoString token;
+
+  while (nsGlobalWindow::TokenizeDialogOptions(token, iter, end)) {
+    if (!result.IsEmpty()) {
+      result.Append(',');
+    }
+
+    result.Append(token);
+  }
+
+  ASSERT_STREQ(test.output, NS_ConvertUTF16toUTF8(result).get()) << "Testing " << test.input;
+}
+
+void runTest(dialog_test& test)
+{
+  NS_ConvertUTF8toUTF16 input(test.input);
+
+  nsAutoString result;
+  nsGlobalWindow::ConvertDialogOptions(input, result);
+
+  ASSERT_STREQ(test.output, NS_ConvertUTF16toUTF8(result).get()) << "Testing " << test.input;
+}
+
+TEST(GlobalWindowDialogOptions, TestDialogTokenize)
+{
+  dialog_test tests[] = {
+    /// Empty strings
+    { "", "" },
+    { " ", "" },
+    { "   ", "" },
+
+    // 1 token
+    { "a", "a" },
+    { " a", "a" },
+    { "  a  ", "a" },
+    { "aa", "aa" },
+    { " aa", "aa" },
+    { "  aa  ", "aa" },
+    { ";", ";" },
+    { ":", ":" },
+    { "=", "=" },
+
+    // 2 tokens
+    { "a=", "a,=" },
+    { "  a=  ", "a,=" },
+    { "  a  =  ", "a,=" },
+    { "aa=", "aa,=" },
+    { "  aa=  ", "aa,=" },
+    { "  aa  =  ", "aa,=" },
+    { ";= ", ";,=" },
+    { "==", "=,=" },
+    { "::", ":,:" },
+
+    // 3 tokens
+    { "a=2", "a,=,2" },
+    { "===", "=,=,=" },
+    { ";:=", ";,:,=" },
+
+    // more
+    { "aaa;bbb:ccc", "aaa,;,bbb,:,ccc" },
+
+    // sentinel
+    { nullptr, nullptr }
+  };
+
+  for (uint32_t i = 0; tests[i].input; ++i) {
+    runTokenizeTest(tests[i]);
+  }
+}
+TEST(GlobalWindowDialogOptions, TestDialogOptions)
+{
+  dialog_test tests[] = {
+    /// Empty strings
+    { "", "" },
+    { " ", "" },
+    { "   ", "" },
+
+    // Name without params
+    { "a", "" },
+    { " a", "" },
+    { "  a  ", "" },
+    { "a=", "" },
+    { "  a=  ", "" },
+    { "  a  =  ", "" },
+
+    // 1 unknown value
+    { "a=2", "" },
+    { " a=2 ", "" },
+    { "  a  =  2 ", "" },
+    { "a:2", "" },
+    { " a:2 ", "" },
+    { "  a  :  2 ", "" },
+
+    // 1 known value, wrong value
+    { "center=2", "" },
+    { "center:2", "" },
+
+    // 1 known value, good value
+    { "center=on", ",centerscreen=1" },
+    { "center:on", ",centerscreen=1" },
+    { " center : on ", ",centerscreen=1" },
+
+    // nonsense stuff
+    { " ; ", "" },
+
+    // sentinel
+    { nullptr, nullptr }
+  };
+
+  for (uint32_t i = 0; tests[i].input; ++i) {
+    runTest(tests[i]);
+  }
+}
diff --git a/dom/base/test/gtest/moz.build b/dom/base/test/gtest/moz.build
new file mode 100644
index 0000000000..cd62303789
--- /dev/null
+++ b/dom/base/test/gtest/moz.build
@@ -0,0 +1,17 @@
+# -*- Mode: python; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# 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/.
+
+UNIFIED_SOURCES += [
+    'TestParserDialogOptions.cpp',
+]
+
+LOCAL_INCLUDES += [
+    '/dom/base'
+]
+
+include('/ipc/chromium/chromium-config.mozbuild')
+
+FINAL_LIBRARY = 'xul-gtest'
diff --git a/dom/base/test/mochitest.ini b/dom/base/test/mochitest.ini
index 4b338d791c..b6fad6710d 100644
--- a/dom/base/test/mochitest.ini
+++ b/dom/base/test/mochitest.ini
@@ -660,6 +660,7 @@ skip-if = buildapp == 'b2g' || toolkit == 'android' #bug 904183 # b2g(bug 904183
 [test_createHTMLDocument.html]
 [test_declare_stylesheet_obsolete.html]
 [test_document_constructor.html]
+[test_document_importNode_document.html]
 [test_domparser_null_char.html]
 [test_domparsing.html]
 [test_elementTraversal.html]
diff --git a/dom/base/test/moz.build b/dom/base/test/moz.build
index 9fdfe9ae43..0e21c2f09d 100644
--- a/dom/base/test/moz.build
+++ b/dom/base/test/moz.build
@@ -36,3 +36,7 @@ MOCHITEST_CHROME_MANIFESTS += [
 BROWSER_CHROME_MANIFESTS += [
     'browser.ini',
 ]
+
+TEST_DIRS += [
+    'gtest',
+]
diff --git a/dom/base/test/test_document_importNode_document.html b/dom/base/test/test_document_importNode_document.html
new file mode 100644
index 0000000000..e33575e844
--- /dev/null
+++ b/dom/base/test/test_document_importNode_document.html
@@ -0,0 +1,32 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=1177914
+-->
+<head>
+  <title>Test for Bug 1177914</title>
+  <script type="text/javascript" src="/MochiKit/MochiKit.js"></script>
+  <script type="text/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=1177914">Mozilla Bug 1177914</a>
+<p id="display"></p>
+<div id="content" style="display: none">
+</div>
+<pre id="test">
+<script class="testbody" type="text/javascript">
+var thrownException = false;
+
+try {
+  document.importNode(document);
+} catch(err) {
+  thrownException = err;
+}
+
+ok(thrownException !== false, "An exception should've been thrown");
+is(thrownException.name, "NotSupportedError", "A NotSupportedError exception should've been thrown");
+</script>
+</pre>
+</body>
+</html>
diff --git a/dom/media/webspeech/synth/SpeechSynthesis.cpp b/dom/media/webspeech/synth/SpeechSynthesis.cpp
index 4601c09267..e09537685a 100644
--- a/dom/media/webspeech/synth/SpeechSynthesis.cpp
+++ b/dom/media/webspeech/synth/SpeechSynthesis.cpp
@@ -73,6 +73,7 @@ NS_IMPL_CYCLE_COLLECTING_RELEASE(SpeechSynthesis)
 SpeechSynthesis::SpeechSynthesis(nsPIDOMWindow* aParent)
   : mParent(aParent)
 {
+  MOZ_ASSERT(aParent->IsInnerWindow());
 }
 
 SpeechSynthesis::~SpeechSynthesis()
diff --git a/dom/tests/mochitest/webcomponents/mochitest.ini b/dom/tests/mochitest/webcomponents/mochitest.ini
index b15f84a522..35dcd73be7 100644
--- a/dom/tests/mochitest/webcomponents/mochitest.ini
+++ b/dom/tests/mochitest/webcomponents/mochitest.ini
@@ -17,6 +17,8 @@ support-files =
 [test_fallback_dest_insertion_points.html]
 [test_detached_style.html]
 [test_dynamic_content_element_matching.html]
+[test_document_adoptnode.html]
+[test_document_importnode.html]
 [test_document_register.html]
 [test_document_register_base_queue.html]
 [test_document_register_lifecycle.html]
diff --git a/dom/tests/mochitest/webcomponents/test_document_adoptnode.html b/dom/tests/mochitest/webcomponents/test_document_adoptnode.html
new file mode 100644
index 0000000000..b00bb4fac7
--- /dev/null
+++ b/dom/tests/mochitest/webcomponents/test_document_adoptnode.html
@@ -0,0 +1,36 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=1177991
+-->
+<head>
+  <title>Test for Bug 1177991</title>
+  <script type="text/javascript" src="/MochiKit/MochiKit.js"></script>
+  <script type="text/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=1177991">Mozilla Bug 1177991</a>
+<p id="display"></p>
+<div id="content" style="display: none">
+
+</div>
+<pre id="test">
+<script class="testbody" type="text/javascript">
+
+var thrownException = false;
+var shadowRoot = document.createElement('a').createShadowRoot();
+
+try {
+  document.adoptNode(shadowRoot);
+} catch(err) {
+  thrownException = err;
+}
+
+ok(thrownException !== false, "A HierarchyRequestError");
+is(thrownException.name, "HierarchyRequestError", "A HierarchyRequestError should've been thrown");
+
+</script>
+</pre>
+</body>
+</html>
diff --git a/dom/tests/mochitest/webcomponents/test_document_importnode.html b/dom/tests/mochitest/webcomponents/test_document_importnode.html
new file mode 100644
index 0000000000..f9042fddfa
--- /dev/null
+++ b/dom/tests/mochitest/webcomponents/test_document_importnode.html
@@ -0,0 +1,37 @@
+<!DOCTYPE HTML>
+<html>
+<!--
+https://bugzilla.mozilla.org/show_bug.cgi?id=1177914
+-->
+<head>
+  <title>Test for Bug 1177914</title>
+  <script type="text/javascript" src="/MochiKit/MochiKit.js"></script>
+  <script type="text/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=1177914">Mozilla Bug 1177914</a>
+<p id="display"></p>
+<div id="content" style="display: none">
+
+</div>
+<pre id="test">
+<script class="testbody" type="text/javascript">
+
+var thrownException = false;
+var shadowRoot = document.createElement('a').createShadowRoot();
+
+try {
+  document.importNode(shadowRoot);
+} catch(err) {
+  thrownException = err;
+}
+
+
+ok(thrownException !== false, "An exception should've been thrown");
+is(thrownException.name, "NotSupportedError", "A NotSupportedError exception should've been thrown");
+
+</script>
+</pre>
+</body>
+</html>
diff --git a/xpfe/appshell/nsXULWindow.cpp b/xpfe/appshell/nsXULWindow.cpp
index ef4fb74242..730c58b0a0 100644
--- a/xpfe/appshell/nsXULWindow.cpp
+++ b/xpfe/appshell/nsXULWindow.cpp
@@ -1962,8 +1962,15 @@ void nsXULWindow::PlaceWindowLayersBehind(uint32_t aLowLevel,
 void nsXULWindow::SetContentScrollbarVisibility(bool aVisible)
 {
   nsCOMPtr<nsPIDOMWindow> contentWin(do_GetInterface(mPrimaryContentShell));
+  if (!contentWin) {
+    return;
+  }
+
+  MOZ_ASSERT(contentWin->IsOuterWindow());
+  contentWin = contentWin->GetCurrentInnerWindow();
   if (contentWin) {
     mozilla::ErrorResult rv;
+
     nsRefPtr<nsGlobalWindow> window = static_cast<nsGlobalWindow*>(contentWin.get());
     nsRefPtr<mozilla::dom::BarProp> scrollbars = window->GetScrollbars(rv);
     if (scrollbars) {