Record UMA metrics for video pixel formats.

Also renumbers VideoFrame::Format enum to remove gaps.

BUG=310272
TBR=danakj

Review URL: https://codereview.chromium.org/47623005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@234019 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 234019
Adding send and receive test apps to Cast

Allowing the user to simulate full cast sender and receiver.
Sender data can either be from file or synthetically generated.
When in Linux, video will be displayed.

Review URL: https://codereview.chromium.org/51213006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@234020 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 234020