Add stats for rendered pixels (sqrt(w*h)) per second:

webrtc/video/receive_statistics_proxy.cc

Index: webrtc/video/receive_statistics_proxy.cc
diff --git a/webrtc/video/receive_statistics_proxy.cc b/webrtc/video/receive_statistics_proxy.cc
index b6063a80afbb1719b2c013a0881a52910da3a38d..536edc4a04742a1c5cda4114cbb0dfa52f0912e2 100644
--- a/webrtc/video/receive_statistics_proxy.cc
+++ b/webrtc/video/receive_statistics_proxy.cc
@@ -10,6 +10,9 @@
 
 #include "webrtc/video/receive_statistics_proxy.h"
 
+#include <cmath>
+
+#include "webrtc/base/checks.h"
 #include "webrtc/system_wrappers/interface/clock.h"
 #include "webrtc/system_wrappers/interface/critical_section_wrapper.h"
 #include "webrtc/system_wrappers/interface/metrics.h"
@@ -21,7 +24,8 @@ ReceiveStatisticsProxy::ReceiveStatisticsProxy(uint32_t ssrc, Clock* clock)
       // 1000ms window, scale 1000 for ms to s.
       decode_fps_estimator_(1000, 1000),
       renders_fps_estimator_(1000, 1000),
-      render_fps_tracker_(100u, 10u) {
+      render_fps_tracker_(100u, 10u),
+      render_pixel_tracker_(100u, 10u) {
   stats_.ssrc = ssrc;
 }
 
@@ -35,12 +39,14 @@ void ReceiveStatisticsProxy::UpdateHistograms() {
     RTC_HISTOGRAM_PERCENTAGE("WebRTC.Video.ReceivedPacketsLostInPercent",
         fraction_lost);
   }
-
-  int render_fps = static_cast<int>(render_fps_tracker_.ComputeTotalRate());
-  if (render_fps > 0)
-    RTC_HISTOGRAM_COUNTS_100("WebRTC.Video.RenderFramesPerSecond", render_fps);
-
   const int kMinRequiredSamples = 200;
+  int samples = static_cast<int>(render_fps_tracker_.TotalSampleCount());
+  if (samples > kMinRequiredSamples) {
+    RTC_HISTOGRAM_COUNTS_100("WebRTC.Video.RenderFramesPerSecond",
+        static_cast<int>(render_fps_tracker_.ComputeTotalRate()));
+    RTC_HISTOGRAM_COUNTS_100000("WebRTC.Video.RenderSqrtPixelsPerSecond",
+        static_cast<int>(render_pixel_tracker_.ComputeTotalRate()));
+  }
   int width = render_width_counter_.Avg(kMinRequiredSamples);
   int height = render_height_counter_.Avg(kMinRequiredSamples);
   if (width != -1) {
@@ -138,6 +144,8 @@ void ReceiveStatisticsProxy::OnDecodedFrame() {
 }
 
 void ReceiveStatisticsProxy::OnRenderedFrame(int width, int height) {
+  RTC_DCHECK_GT(width, 0);
+  RTC_DCHECK_GT(height, 0);
   uint64_t now = clock_->TimeInMilliseconds();
 
   rtc::CritScope lock(&crit_);
@@ -146,6 +154,7 @@ void ReceiveStatisticsProxy::OnRenderedFrame(int width, int height) {
   render_width_counter_.Add(width);
   render_height_counter_.Add(height);
   render_fps_tracker_.AddSamples(1);
+  render_pixel_tracker_.AddSamples(sqrt(width * height));
 }
 
 void ReceiveStatisticsProxy::OnReceiveRatesUpdated(uint32_t bitRate,