This CL adds a slider that can change capture resolution and fps during a call. The camera will no be reconfigured, but the frames will be downscaled/dropped in software by cricket::VideoAdapter in the cricket::VideoCapturer. This is controlled with VideoCapturerAndroid.onOutputFormatRequest(). The slider is turned off by default and can be enabled with a checkbox under 'WebRTC Video Settings'. R=glaznev@webrtc.org Review URL: https://codereview.webrtc.org/1361083002 . Cr-Commit-Position: refs/heads/master@{#10067}