GitLab

Patch by leozwang@chromium.org (https://codereview.chromium.org/12218036/).

This CL JUST enables audio capture on Android, further tunning and
making audio work better might take extra time, I think it's better to
first enable it. A few TODOs are added and minor changes are added into
CL too.

BUG=161417

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@181948 0039d316-1c4b-4281-b951-d872f2087c98