Merge mozilla-inbound to mozilla-central. a=merge

Cargo.lock

accessible/android/SessionAccessibility.cpp

accessible/android/SessionAccessibility.h

accessible/android/moz.build

accessible/base/AccGroupInfo.cpp

accessible/base/AccGroupInfo.h

accessible/generic/Accessible.cpp

accessible/tests/mochitest/attributes.js

accessible/tests/mochitest/attributes/test_obj_group.html

dom/base/Attr.cpp

dom/base/CharacterData.cpp

dom/base/CharacterData.h

dom/base/Comment.h

dom/base/DocumentFragment.h

dom/base/DocumentType.cpp

dom/base/DocumentType.h

dom/base/Element.h

dom/base/FragmentOrElement.cpp

dom/base/GeneratedImageContent.cpp

dom/base/GeneratedImageContent.h