tuna: add ffmpeg codecs

Change-Id: I7238b699a69f8ebb8b8b7aa70d359936653a56fc
Revert "Include specialized copy of libskia for playback of Saved Webpages."

This reverts commit 6eae0292a8aa7a2374f35ebb8a9de801c9421761.

Deprecated in kitkat.

Change-Id: I70fd8284465491f3eadcdc1b595b9de27d7f200d