This got hit in dom/media/test/test_access_control.html

Pushed by bzbarsky@mozilla.com: https://hg.mozilla.org/integration/mozilla-inbound/rev/73a57814a495 Don't enter the compartment of a possibly-gray window object in PostMessageEvent::Run. r=smaug

Pushed by bzbarsky@mozilla.com: https://hg.mozilla.org/integration/mozilla-inbound/rev/d362c6cc036a followup. Add some comments explaining why we're initializing the AutoJSAPI in PostMessageEvent::Run the way we do. DONTBUILD

https://hg.mozilla.org/mozilla-central/rev/73a57814a495 https://hg.mozilla.org/mozilla-central/rev/d362c6cc036a

Comment on attachment 8777071 [details] [diff] [review] Don't enter the compartment of a possibly-gray window object in PostMessageEvent::Run Approval Request Comment [Feature/regressing bug #]: None [User impact if declined]: Possible GC crashes and other such badness [Describe test coverage new/current, TreeHerder]: This codepath is tested in general, yes. [Risks and why]: This is extremely low risk. [String/UUID change made/needed]: None.

Comment on attachment 8777071 [details] [diff] [review] Don't enter the compartment of a possibly-gray window object in PostMessageEvent::Run Crash fix, has stabilized on Nightly for a few weeks, Aurora50+

https://hg.mozilla.org/releases/mozilla-aurora/rev/fc1db61e30cd https://hg.mozilla.org/releases/mozilla-aurora/rev/7f90dcc0445b