GitLab

If hardware overlay processing is skipped for a frame, there's no
way to be sure of the state of the previous frame. Reset
|previous_frame_underlay_rect_| for the next frame.

BUG=Internal b/37644269
CQ_INCLUDE_TRYBOTS=master.tryserver.blink:linux_trusty_blink_rel

Review-Url: https://codereview.chromium.org/2844483004
Cr-Commit-Position: refs/heads/master@{#467754}