Revert 258215 "Remove muting for extreme playbackRates."

> Remove muting for extreme playbackRates.
> 
> Audio was muted below 0.5x and above 4x as the quality degraded
> significantly under the crossfade algorithm. The quality is now much
> better under the WSLOA algorithm (r220343).
> 
> BUG=289354
> R=scherkus@chromium.org
> R=dalecurtis@chromium.org
> 
> Review URL: https://codereview.chromium.org/205093002

TBR=sandersd@chromium.org

Review URL: https://codereview.chromium.org/316733006

git-svn-id: svn://svn.chromium.org/chrome/branches/1916/src@274697 0039d316-1c4b-4281-b951-d872f2087c98
3 files changed