import changes from `dev' branch of rmottola/Arctic-Fox:

- Bug 1196631 - Make JS::ubi::Node::size return 1 by default. r=sfink (9b34eb8a6b)
- Bug 1191236 - Remove extract() methods used by operation forwarding on rooting types r=terrence (fb73375f55)
- Bug 1191236 - Fix UCS canonicalization, r=jonco (fb5f57c838)
- Bug 1196498 - Include objects' [[class]] names in heap snapshots; r=sfink (563e562e95)
- Bug 1194418 - Use only JS::ubi::* interfaces in census analyses; r=sfink (a1374c3a49)
- Bug 1194422 - Expose census traversals to SpiderMonkey embedders; r=sfink (7cd731fffc)
- Bug 1139476 - Part 0: Add a takeCensus method to HeapSnapshot instances; r=sfink,bholley (6aac2ae0dd)
- Bug 1139476 - Part 1: Port live heap census tests to offline heap snapshots; r=sfink (2cd8e13492)
- Bug 1139476 - Part 2: Add test comparing live and offline census results; r=sfink (0db23ac1a0)
-  Bg 1198980 - Make JS::ubi::*::identifier be uint64_t instead of uintptr_t. r=sfink (902c041cb0)
- Bug 1196634 - Part 0: Define a JS::ubi::CoarseType enum; r=sfink (4606fc2845)
- Bug 1196634 - Part 1: Extend the protobuf format for coarseType; r=sfink (4110d46a2f)
- Bug 1196634 - Part 2: Serialize and deserialize coarseType; r=sfink (530e023b48)
- Bug 1196634 - Part 3: Use coarseType() instead of is<T> in census; r=sfink (d077980d77)
- Bug 1196634 - Part 4: Remove JS::ubi::Node::getCanonicalTypeName; r=sfink (4bd7131e4b)
- Bug 1202048 - Root JSONParser explicitly; r=sfink (41a9034849)
- Bug 1175523 - Update most (but not all) tests to use elem.srcObject over .mozSrcObject. r=pehrsons (22a6502d6d)
- Bug 1201190 - Part 3: Mark every consumer of GUARD_OBJECT as MOZ_RAII, r=ehsan (f6c6381a15)
- Bug 1204594 - Use MOZ_RAII to replace GUARD_OBJECT where possible in the GC; r=sfink (cec9b7f607)
- Bug 1205054 - Remove isNullLike and other imprecise null checks; r=sfink (c12a6ed1d4)
- Bug 1205454 - Consolidate the tagged pointer marking methods; r=sfink (7e8a823712)
- js: more shared-build fixes (fdd3b957)

dom/base/nsFrameLoader.cpp

@@ -632,7 +632,7 @@ AllDescendantsOfType(nsIDocShellTreeItem* aParentItem, int32_t aType)
  * A class that automatically sets mInShow to false when it goes
  * out of scope.
  */
-class MOZ_STACK_CLASS AutoResetInShow {
+class MOZ_RAII AutoResetInShow {
   private:
     nsFrameLoader* mFrameLoader;
     MOZ_DECL_USE_GUARD_OBJECT_NOTIFIER