Revert of Don't use webmediaplayer to inform webview about fullscreen change

Revert of Don't use webmediaplayer to inform webview about fullscreen change (https://codereview.chromium.org/275163002/)

Reason for revert:
this will break webview due to poor support of fullscreen api

Original issue's description:
> Don't use webmediaplayer to inform webview about fullscreen change
> 
> Currently we rely on webmediaplayer to inform webview about fullscreen change.
> With https://codereview.chromium.org/277823002/, we no longer need to do so.
> When entering fullscreen, the page will be resized to fullscreen, and that will call Will/DidEnterFullscreen for us.
> When leaving the fullscreen, ToggleFullscreenForTab() will request the tab to exit fullscreen. That should trigger the Resize() call and send Will/DidExitFullscreen for us.
> 
> BUG=367346
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=270005

TBR=trchen@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=367346
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=270141

[qinmin, 2014-05-13 17:43:50]

Created Revert of Don't use webmediaplayer to inform webview about fullscreen
change

[commit-bot: I haz the power, 2014-05-13 17:44:17]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/qinmin@chromium.org/281803002/1

[commit-bot: I haz the power, 2014-05-13 17:48:31]

Change committed as 270141