commit b927e83a996339cf9f6b11220b4ac40337150eac
author dalecurtis@chromium.org <dalecurtis@chromium.org@0039d316-1c4b-4281-b951-d872f2087c98> Mon Apr 28 19:59:23 2014
committer dalecurtis@chromium.org <dalecurtis@chromium.org@0039d316-1c4b-4281-b951-d872f2087c98> Mon Apr 28 19:59:23 2014
tree 25c5c4807022bd7aeb1b1774c692fa433c40ca82
parent f649450a930b11d0d246c30f1329cb6ae74cd52d

Don't double correct for discarded codec delay frames.

The existing code was correcting twice for discarded codec delay
frames.  Once by adjusting the initial timestamp and twice by
discarding those frames before generating the output timestamp.

This change also adds a test helper to AudioFileReader so we can
demux audio files in tests without duplicating code.  As a bonus
it provides some additional coverage to AudioFileReader.

I've also reused several FFmpegCommon methods where possible.

BUG=360961
TEST=Adds opus unit tests. Plus a basic playback test for ogg.
NOTRY=true

Review URL: https://codereview.chromium.org/257563007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@266639 0039d316-1c4b-4281-b951-d872f2087c98