Revert 237311 "Added an "enable-audio-processor" flag and WebRtc..."

> Added an "enable-audio-processor" flag and WebRtcAudioProcessor class.
> 
> 
> This CL is a break-down CL from https://codereview.chromium.org/37793005. As the first step to move WebRtc APM to Chrome, it adds a enable-audio-processor command line flag, the WebRtcAudioProcessor class and its unittest.
> WebRtcAudioProcessor is not hooked up the any of the code in Chrome yet, but it will be exercised and tested by its unittest.
> 
> 
> BUG=264611
> TEST=content_unittest
> 
> Review URL: https://codereview.chromium.org/54383003

TBR=xians@chromium.org

Review URL: https://codereview.chromium.org/88283003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@237334 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 237334