Move video_coding to new Clock interface and remove fake clock implementations from RTP module tests.

TEST=video_coding_unittests, video_coding_integrationtests, rtp_rtcp_unittests, trybots

Review URL: https://webrtc-codereview.appspot.com/1044004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@3393 4adac7df-926f-26a2-2b94-8c16560cd09d

webrtc/modules/rtp_rtcp/source/rtcp_receiver.h

@@ -198,7 +198,7 @@ protected:
 
  private:
   WebRtc_Word32           _id;
-  Clock&           _clock;
+  Clock*                  _clock;
   RTCPMethod              _method;
   WebRtc_Word64           _lastReceived;
   ModuleRtpRtcpImpl&      _rtpRtcp;