Piggybacking simulcast id and ALR experiment id into video content type extension.

webrtc/video/receive_statistics_proxy.h

Index: webrtc/video/receive_statistics_proxy.h
diff --git a/webrtc/video/receive_statistics_proxy.h b/webrtc/video/receive_statistics_proxy.h
index 2e93d70f153770d775a3fd08112b7570ca7cb518..9a6807c4b2c734a5c695510ef57b684930ecd7af 100644
--- a/webrtc/video/receive_statistics_proxy.h
+++ b/webrtc/video/receive_statistics_proxy.h
@@ -20,6 +20,7 @@
 #include "webrtc/modules/video_coding/include/video_coding_defines.h"
 #include "webrtc/rtc_base/criticalsection.h"
 #include "webrtc/rtc_base/moving_max_counter.h"
+#include "webrtc/rtc_base/optional.h"
 #include "webrtc/rtc_base/rate_statistics.h"
 #include "webrtc/rtc_base/ratetracker.h"
 #include "webrtc/rtc_base/thread_annotations.h"
@@ -66,7 +67,9 @@ class ReceiveStatisticsProxy : public VCMReceiveStatisticsCallback,
   void OnReceiveRatesUpdated(uint32_t bitRate, uint32_t frameRate) override;
   void OnFrameCountsUpdated(const FrameCounts& frame_counts) override;
   void OnDiscardedPacketsUpdated(int discarded_packets) override;
-  void OnCompleteFrame(bool is_keyframe, size_t size_bytes) override;
+  void OnCompleteFrame(bool is_keyframe,
+                       size_t size_bytes,
+                       VideoContentType content_type) override;
   void OnFrameBufferTimingsUpdated(int decode_ms,
                                    int max_decode_ms,
                                    int current_delay_ms,
@@ -98,16 +101,33 @@ class ReceiveStatisticsProxy : public VCMReceiveStatisticsCallback,
     SampleCounter() : sum(0), num_samples(0) {}
     void Add(int sample);
     int Avg(int64_t min_required_samples) const;
+    int Max() const;
     void Reset();
+    void Add(const SampleCounter& other);
 
    private:
     int64_t sum;
     int64_t num_samples;
+    rtc::Optional<int> max;
   };
+
   struct QpCounters {
     SampleCounter vp8;
   };
 
+  struct ContentSpecificStats {
+    void Add(const ContentSpecificStats& other);
+
+    SampleCounter e2e_delay_counter;
+    SampleCounter interframe_delay_counter;
+    int64_t flow_duration_ms = 0;
+    int64_t total_media_bytes = 0;
+    SampleCounter received_width;
+    SampleCounter received_height;
+    SampleCounter qp_counter;
+    FrameCounts frame_counts;
+  };
+
   void UpdateHistograms() EXCLUSIVE_LOCKS_REQUIRED(crit_);
 
   void QualitySample() EXCLUSIVE_LOCKS_REQUIRED(crit_);
@@ -140,24 +160,16 @@ class ReceiveStatisticsProxy : public VCMReceiveStatisticsCallback,
   rtc::RateTracker render_fps_tracker_ GUARDED_BY(crit_);
   rtc::RateTracker render_pixel_tracker_ GUARDED_BY(crit_);
   rtc::RateTracker total_byte_tracker_ GUARDED_BY(crit_);
-  SampleCounter render_width_counter_ GUARDED_BY(crit_);
-  SampleCounter render_height_counter_ GUARDED_BY(crit_);
   SampleCounter sync_offset_counter_ GUARDED_BY(crit_);
   SampleCounter decode_time_counter_ GUARDED_BY(crit_);
   SampleCounter jitter_buffer_delay_counter_ GUARDED_BY(crit_);
   SampleCounter target_delay_counter_ GUARDED_BY(crit_);
   SampleCounter current_delay_counter_ GUARDED_BY(crit_);
   SampleCounter delay_counter_ GUARDED_BY(crit_);
-  SampleCounter e2e_delay_counter_video_ GUARDED_BY(crit_);
-  SampleCounter e2e_delay_counter_screenshare_ GUARDED_BY(crit_);
-  SampleCounter interframe_delay_counter_video_ GUARDED_BY(crit_);
-  SampleCounter interframe_delay_counter_screenshare_ GUARDED_BY(crit_);
-  int64_t e2e_delay_max_ms_video_ GUARDED_BY(crit_);
-  int64_t e2e_delay_max_ms_screenshare_ GUARDED_BY(crit_);
-  int64_t interframe_delay_max_ms_video_  GUARDED_BY(crit_);
-  int64_t interframe_delay_max_ms_screenshare_  GUARDED_BY(crit_);
   mutable rtc::MovingMaxCounter<int> interframe_delay_max_moving_
       GUARDED_BY(crit_);
+  std::map<VideoContentType, ContentSpecificStats> content_specific_stats_
+      GUARDED_BY(crit_);
   MaxCounter freq_offset_counter_ GUARDED_BY(crit_);
   int64_t first_report_block_time_ms_ GUARDED_BY(crit_);
   ReportBlockStats report_block_stats_ GUARDED_BY(crit_);