Wire up target_media_bitrate in VideoSendStream.

Also wires up target_enc_bitrate in WebRtcVideoEngine2.

BUG=1667,1788
R=mflodman@webrtc.org, stefan@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/42479004

Cr-Commit-Position: refs/heads/master@{#8515}
git-svn-id: http://webrtc.googlecode.com/svn/trunk@8515 4adac7df-926f-26a2-2b94-8c16560cd09d

webrtc/modules/video_coding/main/interface/video_coding.h

@@ -81,7 +81,8 @@ public:
         kReferenceSelection
     };
 
-    static VideoCodingModule* Create();
+    static VideoCodingModule* Create(
+        VideoEncoderRateObserver* encoder_rate_observer);
 
     static VideoCodingModule* Create(Clock* clock, EventFactory* event_factory);
 

webrtc/modules/video_coding/main/interface/video_coding_defines.h

@@ -148,6 +148,12 @@ class VCMProtectionCallback {
   }
 };
 
+class VideoEncoderRateObserver {
+ public:
+  virtual ~VideoEncoderRateObserver() {}
+  virtual void OnSetRates(uint32_t bitrate_bps, int framerate) = 0;
+};
+
 // Callback class used for telling the user about what frame type needed to continue decoding.
 // Typically a key frame when the stream has been corrupted in some way.
 class VCMFrameTypeCallback {