This CL should be the last one in a series to finally unblock camera texture capture. The SurfaceTexture.updateTexImage() calls are moved from the video renderers into MediaCodecVideoDecoder, and the destructor of the texture frames will signal MediaCodecVideoDecoder that the frame has returned. This CL also removes the SurfaceTexture from the native handle and only exposes the texture matrix instead, because only the video source should access the SurfaceTexture. BUG=webrtc:4993 R=glaznev@webrtc.org, perkj@webrtc.org Review URL: https://codereview.webrtc.org/1378033003 . Cr-Commit-Position: refs/heads/master@{#10203}