Remove an outdated timeupdate hack android uses to start video painting

Remove an outdated timeupdate hack android uses to start video painting

OnTimeChanged() no longer setDisplayMode(), so this hack is no longer working for quite some time.
Media element should know when to start painting the video frame when  playback state changes.

BUG=504773
Committed: https://crrev.com/c6145c33172101a41953d6c9e2a6939345901949
Cr-Commit-Position: refs/heads/master@{#342724}

[qinmin, 2015-08-10 21:49:29]

qinmin@chromium.org changed reviewers:
+ xhwang@chromium.org

[qinmin, 2015-08-10 21:49:29]

PTAL

[xhwang, 2015-08-10 21:56:11]

lgtm

[qinmin, 2015-08-10 21:56:34]

The CQ bit was checked by qinmin@chromium.org

[commit-bot: I haz the power, 2015-08-10 21:56:53]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1271313006/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1271313006/1

[commit-bot: I haz the power, 2015-08-10 23:00:43]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-08-10 23:01:33]

Patchset 1 (id:??) landed as
https://crrev.com/c6145c33172101a41953d6c9e2a6939345901949
Cr-Commit-Position: refs/heads/master@{#342724}