Re-land of https://codereview.chromium.org/107443002:

Adding an audio-level WebRTC test to verify muting and playback.

This test uses the stats API to measure the audioOutputLevel. Since the
content browsertests always uses fake devices we can adapt the test to
look for that particular signal.

This test is primarily intended to run on Android but will work on
desktop as well. Tested by running manually on a Nexus 7 device
at my workstation.

BUG=325164
TBR=wjia@chromium.org

Review URL: https://codereview.chromium.org/101293005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@239490 0039d316-1c4b-4281-b951-d872f2087c98
Blink roll 163292:163433

http://build.chromium.org/f/chromium/perf/dashboard/ui/changelog_blink.html?url=/trunk&range=163293:163433&mode=html
TBR=
BUG=

Review URL: https://codereview.chromium.org/105693008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@239491 0039d316-1c4b-4281-b951-d872f2087c98
Update .DEPS.git

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@239492 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 239492