Merge inbound to central, a=merge

accessible/generic/DocAccessible.cpp

...ser/components/extensions/test/browser/browser-common.ini

browser/components/sessionstore/test/browser.ini

...components/uitour/test/browser_UITour_availableTargets.js

browser/extensions/screenshots/bootstrap.js

browser/extensions/screenshots/install.rdf

browser/extensions/screenshots/moz.build

browser/extensions/screenshots/test/browser/.eslintrc.js

browser/extensions/screenshots/test/browser/.eslintrc.yml

.../screenshots/test/browser/browser_screenshots_ui_check.js

browser/extensions/screenshots/test/browser/head.js

...sions/screenshots/webextension/_locales/ach/messages.json

...nsions/screenshots/webextension/_locales/ar/messages.json

...sions/screenshots/webextension/_locales/ast/messages.json

...nsions/screenshots/webextension/_locales/az/messages.json

...nsions/screenshots/webextension/_locales/be/messages.json

...nsions/screenshots/webextension/_locales/bg/messages.json

...ons/screenshots/webextension/_locales/bn_BD/messages.json

...nsions/screenshots/webextension/_locales/ca/messages.json

...sions/screenshots/webextension/_locales/cak/messages.json