Add the option of compressing speech input audio using FLAC.
In the process, added a generic AudioEncoder interface which could create the requested codec.
Right now the codec is set to FLAC. In a future CL, we'll determine the codec to use dynamically
based on bandwidth considerations.

This CL depends on http://codereview.chromium.org/6205006/ going in first.

BUG=61677
TEST=none

Review URL: http://codereview.chromium.org/6111009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@71599 0039d316-1c4b-4281-b951-d872f2087c98
6 files changed