Per discussion in PR #2875 our NPAPI implementation doesn't support plugins
using GTK3 anyway so there's no point in keeping this footgun for a GTK3 setup.
The pref should not be conditional on which plugin or GTK version is in use. If
Windows users want Flash in-process, or GTK3 users want in-process plugins, we
should let them. If it breaks, they at least have half a browser.
While at it the checks for accessibility hardware support have also been taken
out, because they're only relevant for Flash anyway. Being able to disable OOP
should not depend on whether you use a11y.
https://bugzilla.mozilla.org/show_bug.cgi?id=1342012
Support import from timeout handlers by associating the initiating script with the compiled JSScript.
Fix error message that covers all import() failures that don't throw a JS exception.
https://bugzilla.mozilla.org/show_bug.cgi?id=1331662
Partial - Replace nsJSUtils::EvaluateString calls by ExecutionContext scopes.
Left EvaluateString() in nsXBLProtoImplField.cpp until ExecutionContext errors can be fixed.
(cherry picked from commit 22fcfc77971a9bb204df664c474681f4dcf54211)