This seems to make a big difference when running tests with WARP.
e.g. Assertion failure: frameInfo.mDocFramesSeen == frameInfo.mDocFramesTotal,
at z:/build/build/src/gfx/webrender_bindings/RenderThread.cpp:303
and various other browser chrome test failures.
The original problem that added this flag only impacted AMD hardware as I
recall and we are unlikely to ever be running on WARP in production anyways.
When WARP is forced we also don't disable INTERNAL_THREADING_OPTIMIZATIONS.
Differential Revision: https://phabricator.services.mozilla.com/D42214
--HG--
extra : moz-landing-system : lando
0d744a9591