Simplifying VideoReceiver and JitterBuffer.

Removing frame_buffers_ array and dual-receiver mechanism. Also adding
some thread annotations to VCMJitterBuffer.

R=stefan@webrtc.org
BUG=4014

Review URL: https://webrtc-codereview.appspot.com/27239004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@7735 4adac7df-926f-26a2-2b94-8c16560cd09d

webrtc/modules/video_coding/main/source/receiver_unittest.cc

@@ -81,8 +81,8 @@ class TestVCMReceiver : public ::testing::Test {
 
   bool DecodeNextFrame() {
     int64_t render_time_ms = 0;
-    VCMEncodedFrame* frame = receiver_.FrameForDecoding(0, render_time_ms,
-                                                        false, NULL);
+    VCMEncodedFrame* frame =
+        receiver_.FrameForDecoding(0, render_time_ms, false);
     if (!frame)
       return false;
     receiver_.ReleaseFrame(frame);