The wait sync token completion callback is called while commands are
being processed in the releasing context. Therefore, it is not safe to
call MakeCurrent on the waiting context and pull texture updates from
MailboxManagerSync. Moreoever, the wait sync token command is executed
again when the context is scheduled, and PullTextureUpdates will be
called there.
R=jbauman@chromium.org
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.android:android_optional_gpu_tests_rel;master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel
Review-Url: https://codereview.chromium.org/2726743002
Cr-Commit-Position: refs/heads/master@{#454728}
6125ed888b