The guts of the video renderer logic that relate to timing and queuing of...

The guts of the video renderer logic that relate to timing and queuing of frames have been moved into a base class.  This class now
simply interracts with the delegate to paint the current frame when a repaint is needed.
Review URL: http://codereview.chromium.org/20345

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@10296 0039d316-1c4b-4281-b951-d872f2087c98