GitLab

ReadyState has never been suficient to test whether a video frame is
actually present. Instead we need to know when the frame has actually
been delivered to the compositor.

This patch updates HTMLVideoElement to query a new WebMediaPlayer method
which exposes the compositor's knowledge of the video frame.

Note: This patch also fixes some spurious logs and HTMLVideoElement tests
that were silently doing nothing.

BUG=974012,974190
TEST=new unittest.
TBR=eae

Change-Id: I1df54491c1fd7c2246ce0f60bc6e794b8b84476a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1659490
Commit-Queue: Dale Curtis <dalecurtis@chromium.org>
Reviewed-by: Mounir Lamouri <mlamouri@chromium.org>
Cr-Commit-Position: refs/heads/master@{#672682}