Merge inbound to central, a=merge

browser/base/content/nsContextMenu.js

browser/components/downloads/content/downloads.js

browser/components/preferences/in-content/privacy.js

browser/components/preferences/in-content/privacy.xul

browser/locales/en-US/chrome/browser/preferences/privacy.dtd

browser/modules/ContextMenu.jsm

docshell/base/nsDocShell.h

dom/base/DOMIntersectionObserver.cpp

dom/base/nsDeprecatedOperationList.h

dom/base/nsDocument.cpp

dom/base/nsFrameLoader.cpp

dom/base/nsGlobalWindow.cpp

dom/base/nsIDocument.h

dom/base/test/mochitest.ini

dom/base/test/test_bug1399605.html

dom/base/test/test_window_content.html

dom/bindings/Codegen.py

dom/bindings/SimpleGlobalObject.cpp

dom/bindings/parser/WebIDL.py

dom/bindings/test/TestBindingHeader.h