Revert 172659 "Get the WebUserMediaClient from WebFrameClient in..."

Causes failures on webkit gpu bots for performance_browser_tests 

> Get the WebUserMediaClient from WebFrameClient instead of WebViewClient.
> 
> BUG=304341
> 
> Review URL: https://codereview.chromium.org/254523006

TBR=jam@chromium.org

Review URL: https://codereview.chromium.org/253643003

git-svn-id: svn://svn.chromium.org/blink/trunk@172686 bbb929c8-8fbe-4397-9dbb-9b2b20218538