Add unit test for disabling deferred canvas rendering while hibernating

Crash was already inavertently fixed by
https://codereview.chromium.org/1520123002/
This change adds a test that would have caught the crash in the
first place.

BUG=568583

Review URL: https://codereview.chromium.org/1527023002

Cr-Commit-Position: refs/heads/master@{#365326}
1 file changed