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

- Bug 1121855 - Fix camera crash. r=aosmond (6ad4335ae)
- Bug 1139721 - Fix camera memory leaks for onfacedetected events, failed initializations and capabilities. r=mikeh (663bbde8c)
- Bug 1165729 - Check SetCapacity return value in nsSMILAnimationFunction::GetValues. r=dholbert (100ecf2f7)
- Bug 968520 - Add mozilla::fallible to Fallible{Auto,}TArray::SetCapacity calls. r=froydnj (2c120f71a)
- Scrollbar thumbs can overlap scrollbar arrows during APZ scrolling. (bug 1152469, r=botond,mstange) (a2e9ac1bf)
- Bug 1148889 - Treat subclasses of scrollframes as animated geometry roots. r=mstange (434719455)
- Bug 1155025. Make the root layer on fennec have null scroll id with containerless scrolling. r=mstange (eb1bb3acd)
- remove test (63f014d13)
- Bug 1151306 - Add a reftest. r=roc (56c4137ae)
- Bug 1151145 - Add a reftest. r=jrmuizel (9684c3f0a)
- Bug 1150021. Make sure that boxes inside vertical RTL boxes are placed on the right. r=roc (c4b3e7e06)
- Bug 1156129 - Take border radius into account when calculating the bounds of border display items. r=roc (35b70f9a8)
- Bug 1152902 part 2. Add a fast path for the case when a Promise is resolved with another Promise. r=nsm (33a210977)

dom/base/nsDOMMutationObserver.cpp

@@ -747,7 +747,7 @@ nsDOMMutationObserver::HandleMutation()
 
   mozilla::dom::Sequence<mozilla::dom::OwningNonNull<nsDOMMutationRecord> >
     mutations;
-  if (mutations.SetCapacity(mPendingMutationCount)) {
+  if (mutations.SetCapacity(mPendingMutationCount, mozilla::fallible)) {
     // We can't use TakeRecords easily here, because it deals with a
     // different type of array, and we want to optimize out any extra copying.
     nsRefPtr<nsDOMMutationRecord> current;