Merge m-c to autoland. a=merge

.eslintignore

accessible/moz.build

accessible/tests/browser/browser.ini

accessible/tests/browser/e10s/browser.ini

accessible/tests/browser/e10s/head.js

accessible/tests/browser/events.js

accessible/tests/browser/head.js

accessible/tests/browser/shared-head.js

accessible/tests/browser/states/browser.ini

accessible/tests/browser/states/browser_test_link.js

accessible/tests/browser/states/head.js

accessible/tests/mochitest/states/test_link.html

devtools/client/inspector/grids/components/Grid.js

devtools/client/inspector/grids/components/GridOutline.js

dom/base/DOMIntersectionObserver.cpp

image/imgLoader.cpp

js/src/frontend/BytecodeEmitter.cpp

js/src/frontend/BytecodeEmitter.h

js/src/jit-test/tests/parser/bug-1355046.js

layout/forms/test/test_bug348236.html