Android video: support copying video to WebGL when video is playing remotely.
WebGL and Canvas also should draw a fixed VideoFrame showing a Cast logo, which replaces the local video
frames in embedded <video> elements whenever a video is being played remotely.
TEST=Run http://browsertests.herokuapp.com/media/mdn_samples_webgl_sample8/index.html on Nexus 5.
BUG=284478
NOTRY=true
Review URL: https://codereview.chromium.org/
212183005
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@260382 0039d316-1c4b-4281-b951-d872f2087c98