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

- Bug 1193786 - crash in mozilla::dom::Element::FindAttrValueIn, r=marcoz (1f03b9594f)
- bug 1172516 - fix firing caret move events for proxied accessibles r=lsocks (6a62915a27)
- Bug 582024 - ARIA active-descendant should work for ARIA owned elements, r=yzen (4fc7049fe1)
- Bug 1212457 - crash at ARIARowAccessible::GroupPosition(), r=marcoz (dd058e3dcd)
- bit of 1139049 (ae765adc6a)
- Bug 1221542, bug 1221543 - crash in mozilla::a11y::DocAccessible::SeizeChild/PutChildrenBack, r=davidb (8a35b14523)
- Bug 1105611 - HyperTextAccessible should set DOM range outside of pseudo elements r=surkov (19e2cf65cd)
- Bug 1177765 - Add xmlroles for MathML. r=surkov (381201ae27)
- Bug 1176683 - crash in mozilla::a11y::HyperTextAccessible::LandmarkRole() const, r=marcoz (f3fd977d35)
- Bug 1176123 - Add NODE_CHILD_OF/NODE_PARENT_OF relations to mroot. r=surkov (36f08faa15)
- Bug 1179483 - Fix crash in mozilla::a11y::HyperTextAccessible::RelationByType. r=MarcoZ (fec7fde5b3)
- Bug 1177765 - Make nsIMathMLFrame expose the fence and separator properties of operators. r=karlt (91e45d9980)
- Bug 1139709. Cache nsMathMLContainerFrame's intrinsic width. r=mats (ac40d07d89)
- code style (c5f50fc0c3)
- Bug 1226875 - Remove nsIFrame::GetLastChild(). r=mats (9b88566b77)
- pointer style (6a5b9599f4)
- Bug 1177093 - mathfont.properties does not need to be preprocessed after Bug 1000745 r=fred.wang (d114e285a1)
- Bug 1224951 - Part 2: Fix -Wunreachable-code warnings in layout. r=dholbert (5854ee5e3e)
- Bug 1141443 - Remove unused rpcns4 from OS_LIBS. r=mshal (1a5ccc985b)
- bug 1218762 - proxy ia2Accessible::scrollTo{,Point}() r=davidb (db1db8e703)
- Bug 1182208 - Add support for android scrolling and range accessibility actions. r=mfinkle r=yzen (29df38ee29)
- Bug 1144516 - Remove offset of mozbrowser iframe. r=yzen (c7473a8feb)
- Bug 1176292 - Send 'toggle-shade' control event to content on 3 finger triple tap. r=yzen (536932619a)
- Bug 1182222 - Make Layerview support accessibility HTML navigation. r=yzen r=mfinkle (2beb411989)
- Bug 1203697 - Add braille navigation. r=yzen r=mfinkle (d5a513e79e)
- Bug 1209054 - Make 2 finger tap toggle pause speech. r=yzen (28bc8c16a6)
- Bug 1214398 - Add highlight box to doc body if it is available and set z-index. r=yzen (9cca205849)
- Bug 1182214 - Update highlight rect as you scroll. r=yzen (6d2738366a)
- Bug 1182214 - Follow-up to fix Presentation.displayedAccessibles getter. r=me CLOSED TREE (6dd8ec3652)
- Bug 1212528 - ensuring first seen document in ancestry is announced first. r=marcoz (fb8e9bc406)
- Bug 1217038 - Remove for-each and legacy array comprehension from accessible/. r=yzen (810590b5d3)
- Bug 1220860 - fixing an error with getting documentElement on AccessFu stop. r=eeejay (4a35fabc3d)
- Bug 1169019 - Removed screenreader announcement from gecko. r=yzen (2b1732cddc)
- Bug 1211122 - ensuring that we check position against an actual doc/dialog on doc load event. r=marcoz (78b7cc8a77)
- Bug 1019432 - [AccessFu] Only capture explore by touch events in Android. r=yzen (eee4b09c72)
- Bug 1182311 - Make 3 finger triple tap more reliable. r=yzen (7cf926a839)
- Bug 1201146 - Introduce "Section" traversal rule. r=yzen (253d53ec8d)
- Bug 1203283 - Introduce Android "Control" traversal rule. r=yzen (4d14ffa973)

layout/mathml/nsMathMLmfencedFrame.cpp

@@ -391,7 +391,7 @@ nsMathMLmfencedFrame::Reflow(nsPresContext*          aPresContext,
   }
 
   if (isRTL) {
-    childFrame = this->GetLastChild(nsIFrame::kPrincipalList);
+    childFrame = this->GetChildList(nsIFrame::kPrincipalList).LastChild();
   } else {
     childFrame = firstChild;
   }