Implement framesEncoded stat in video send ssrc stats.

webrtc/media/base/mediachannel.h

Index: webrtc/media/base/mediachannel.h
diff --git a/webrtc/media/base/mediachannel.h b/webrtc/media/base/mediachannel.h
index b71a309233546f941150431bf5df4aca8f46b095..68f7df179c2db20edad713fe97536bea43567de0 100644
--- a/webrtc/media/base/mediachannel.h
+++ b/webrtc/media/base/mediachannel.h
@@ -665,8 +665,8 @@ struct VideoSenderInfo : public MediaSenderInfo {
         adapt_reason(0),
         adapt_changes(0),
         avg_encode_ms(0),
-        encode_usage_percent(0) {
-  }
+        encode_usage_percent(0),
+        frames_encoded(0) {}
 
   std::vector<SsrcGroup> ssrc_groups;
   std::string encoder_implementation_name;
@@ -684,6 +684,7 @@ struct VideoSenderInfo : public MediaSenderInfo {
   int adapt_changes;
   int avg_encode_ms;
   int encode_usage_percent;
+  uint32_t frames_encoded;
 };
 
 struct VideoReceiverInfo : public MediaReceiverInfo {