Report video and network stats averaged over 1s, and create corresponding UMA metrics.

remoting/client/plugin/chromoting_instance.cc

Index: remoting/client/plugin/chromoting_instance.cc
diff --git a/remoting/client/plugin/chromoting_instance.cc b/remoting/client/plugin/chromoting_instance.cc
index c32d31ded27bcd4d333f047d9af82c1536d5442a..df8c7ee745ee9f65f658d57a469feedcd825a4cf 100644
--- a/remoting/client/plugin/chromoting_instance.cc
+++ b/remoting/client/plugin/chromoting_instance.cc
@@ -32,6 +32,7 @@
 #include "ppapi/cpp/dev/url_util_dev.h"
 #include "ppapi/cpp/image_data.h"
 #include "ppapi/cpp/input_event.h"
+#include "ppapi/cpp/private/uma_private.h"
 #include "ppapi/cpp/rect.h"
 #include "ppapi/cpp/var_array_buffer.h"
 #include "ppapi/cpp/var_dictionary.h"
@@ -73,6 +74,26 @@ const int kPerfStatsIntervalMs = 1000;
 // URL scheme used by Chrome apps and extensions.
 const char kChromeExtensionUrlScheme[] = "chrome-extension";
 
+// The boundary value for the FPS histogram: we don't expect video frame-rate to
+// be greater than 40fps.
+// Histograms expect samples to be less than the boundary value, so set to 41.
+const int kMaxFrameRate = 41;
+// For bandwidth, we'll use a histogram ranging from 0 to 1MB/s, spread across
+// 1000 buckets.
+// Histograms are log-scaled by default. This results in fine-grained buckets at
+// lower values and wider-ranged buckets closer to the maximum.
+// Values above the maximum defined here end up in the right-most bucket.
+// See $/src/base/metrics/histogram.h for more details.
+const int kBandwidthHistogramMin = 1;
+const int kBandwidthHistogramMax = 1024000;
+const int kBandwidthHistogramNumBuckets = 1000;
+
+// For the latency metrics, we'll set the max histogram value to 20,000ms, split
+// over 1000 buckets.
+const int kLatencyHistogramMin = 1;
+const int kLatencyHistogramMax = 20000;
+const int kLatencyHistogramNumBuckets = 1000;
+
 #if defined(USE_OPENSSL)
 // Size of the random seed blob used to initialize RNG in libjingle. Libjingle
 // uses the seed only for OpenSSL builds. OpenSSL needs at least 32 bytes of
@@ -1054,16 +1075,42 @@ void ChromotingInstance::SendPerfStats() {
                             weak_factory_.GetWeakPtr()),
       base::TimeDelta::FromMilliseconds(kPerfStatsIntervalMs));
 
+  // Update performance stats, averaged over the past few seconds.
+  // These are eventually upstreamed to the web-app, and also available for
+  // display to the user.
   scoped_ptr<base::DictionaryValue> data(new base::DictionaryValue());
   ChromotingStats* stats = video_renderer_->GetStats();
-  data->SetDouble("videoBandwidth", stats->video_bandwidth()->Rate());
-  data->SetDouble("videoFrameRate", stats->video_frame_rate()->Rate());
+  data->SetDouble("videoBandwidth",
+    stats->video_Bps_webapp()->Rate());
+  data->SetDouble("videoFrameRate", stats->video_fps_webapp()->Rate());
   data->SetDouble("captureLatency", stats->video_capture_ms()->Average());
   data->SetDouble("encodeLatency", stats->video_encode_ms()->Average());
   data->SetDouble("decodeLatency", stats->video_decode_ms()->Average());
   data->SetDouble("renderLatency", stats->video_paint_ms()->Average());
   data->SetDouble("roundtripLatency", stats->round_trip_ms()->Average());
   PostLegacyJsonMessage("onPerfStats", data.Pass());
+
+  // Update UMA histograms for video frame-rate, bandwidth and latencies.
+  // These metrics will be averaged over the last second.
+  pp::UMAPrivate uma_interface(this);
+  uma_interface.HistogramEnumeration(
+      "Chromoting.Video.FrameRate", stats->video_Bps_UMA()->Rate(),
+      kMaxFrameRate);
+  uma_interface.HistogramEnumeration(
+      "Chromoting.Video.FrameRate",
+      stats->video_packets_per_s_UMA()->Rate(), kMaxFrameRate);
+  uma_interface.HistogramCustomCounts("Chromoting.Video.Bandwidth",
+    stats->video_Bps_UMA()->Rate(), kBandwidthHistogramMin,
+    kBandwidthHistogramMax, kBandwidthHistogramNumBuckets);
+  uma_interface.HistogramCustomTimes("Chromoting.Video.CaptureLatency",
+    stats->video_capture_ms()->Average(), kLatencyHistogramMin,
+    kLatencyHistogramMax, kLatencyHistogramNumBuckets);
+  uma_interface.HistogramCustomTimes("Chromoting.Video.EncodeLatency",
+    stats->video_encode_ms()->Average(), kLatencyHistogramMin,
+    kLatencyHistogramMax, kLatencyHistogramNumBuckets);
+  uma_interface.HistogramCustomTimes("Chromoting.Video.RoundTripLatency",
+    stats->round_trip_ms()->Average(), kLatencyHistogramMin,
+    kLatencyHistogramMax, kLatencyHistogramNumBuckets);
 }
 
 // static