Add sent framerates to histogram stats:

webrtc/modules/video_coding/main/source/media_optimization.h

Index: webrtc/modules/video_coding/main/source/media_optimization.h
diff --git a/webrtc/modules/video_coding/main/source/media_optimization.h b/webrtc/modules/video_coding/main/source/media_optimization.h
index 3ab31f29af7688f60c660303b0a07fd43f701410..3f1c179e45821252541dc7a47d5f60acb5c8f4c2 100644
--- a/webrtc/modules/video_coding/main/source/media_optimization.h
+++ b/webrtc/modules/video_coding/main/source/media_optimization.h
@@ -139,6 +139,8 @@ class MediaOptimization {
 
   uint32_t SentFrameRateInternal() EXCLUSIVE_LOCKS_REQUIRED(crit_sect_);
 
+  void UpdateHistograms();
+
   // Protect all members.
   rtc::scoped_ptr<CriticalSectionWrapper> crit_sect_;
 
@@ -173,6 +175,8 @@ class MediaOptimization {
   bool video_suspended_ GUARDED_BY(crit_sect_);
   int suspension_threshold_bps_ GUARDED_BY(crit_sect_);
   int suspension_window_bps_ GUARDED_BY(crit_sect_);
+  size_t sent_frames_ GUARDED_BY(crit_sect_);
+  int64_t first_sent_frame_time_ms_ GUARDED_BY(crit_sect_);
 };
 }  // namespace media_optimization
 }  // namespace webrtc