Add watch time metrics for HTML5 media playback.

content/browser/media/media_internals.cc

Index: content/browser/media/media_internals.cc
diff --git a/content/browser/media/media_internals.cc b/content/browser/media/media_internals.cc
index 3ef867386b38ba2c1d3df7d8e3b1e29f5092261b..ae0a737fb4d119263b81ed2c395b68cfc755ac4b 100644
--- a/content/browser/media/media_internals.cc
+++ b/content/browser/media/media_internals.cc
@@ -25,6 +25,7 @@
 #include "content/public/browser/web_ui.h"
 #include "media/base/audio_parameters.h"
 #include "media/base/media_log_event.h"
+#include "media/blink/watch_time_reporter.h"
 #include "media/filters/gpu_video_decoder.h"
 
 #if !defined(OS_ANDROID)
@@ -289,6 +290,15 @@ class MediaInternals::MediaInternalsUMAHandler {
                        const media::MediaLogEvent& event);
 
  private:
+  struct WatchTimeInfo {
+    base::TimeDelta all_watch_time = media::kNoTimestamp;
+    base::TimeDelta mse_watch_time = media::kNoTimestamp;
+    base::TimeDelta eme_watch_time = media::kNoTimestamp;
+    base::TimeDelta src_watch_time = media::kNoTimestamp;
+    base::TimeDelta ac_watch_time = media::kNoTimestamp;
+    base::TimeDelta battery_watch_time = media::kNoTimestamp;
+  };
+
   struct PipelineInfo {
     bool has_pipeline = false;
     media::PipelineStatus last_pipeline_status = media::PIPELINE_OK;
@@ -299,6 +309,7 @@ class MediaInternals::MediaInternalsUMAHandler {
     std::string audio_codec_name;
     std::string video_codec_name;
     std::string video_decoder;
+    WatchTimeInfo watch_time_info;
   };
 
   // Helper function to report PipelineStatus associated with a player to UMA.
@@ -307,6 +318,23 @@ class MediaInternals::MediaInternalsUMAHandler {
   // Helper to generate PipelineStatus UMA name for AudioVideo streams.
   std::string GetUMANameForAVStream(const PipelineInfo& player_info);
 
+  // Saves the watch time info from |event| under |key| at |watch_time| if |key|
+  // is present in |event.params|.
+  void MaybeSaveWatchTime(const media::MediaLogEvent& event,
+                          const char* key,
+                          base::TimeDelta* watch_time) {
+    if (!event.params.HasKey(key))
+      return;
+
+    double in_seconds;
+    const bool result =
+        event.params.GetDoubleWithoutPathExpansion(key, &in_seconds);
+    DCHECK(result);
+    *watch_time = base::TimeDelta::FromSecondsD(in_seconds);
+
+    DVLOG(2) << "Saved watch time for " << key << " of " << *watch_time;
+  }
+
   // Key is player id.
   typedef std::map<int, PipelineInfo> PlayerInfoMap;
 
@@ -369,6 +397,29 @@ void MediaInternals::MediaInternalsUMAHandler::SavePlayerState(
         event.params.GetBoolean("video_dds", &player_info[event.id].video_dds);
       }
       break;
+    case media::MediaLogEvent::Type::WATCH_TIME_UPDATE: {
+      DVLOG(2) << "Processing watch time update.";
+      WatchTimeInfo& wti = player_info[event.id].watch_time_info;
+      MaybeSaveWatchTime(event,
+                         media::WatchTimeReporter::kHistogramAudioVideoAll,
+                         &wti.all_watch_time);
+      MaybeSaveWatchTime(event,
+                         media::WatchTimeReporter::kHistogramAudioVideoMse,
+                         &wti.mse_watch_time);
+      MaybeSaveWatchTime(event,
+                         media::WatchTimeReporter::kHistogramAudioVideoEme,
+                         &wti.eme_watch_time);
+      MaybeSaveWatchTime(event,
+                         media::WatchTimeReporter::kHistogramAudioVideoSrc,
+                         &wti.src_watch_time);
+      MaybeSaveWatchTime(event,
+                         media::WatchTimeReporter::kHistogramAudioVideoBattery,
+                         &wti.battery_watch_time);
+      MaybeSaveWatchTime(event,
+                         media::WatchTimeReporter::kHistogramAudioVideoAc,
+                         &wti.ac_watch_time);
+      break;
+    }
     default:
       break;
   }
@@ -446,6 +497,22 @@ void MediaInternals::MediaInternalsUMAHandler::ReportUMAForPipelineStatus(
     UMA_HISTOGRAM_BOOLEAN("Media.VideoDecoderFallback",
                           player_info.video_decoder_changed);
   }
+
+// Use a macro instead of a function so we can use the histogram macro (which
+// checks that the uma name is a static value).
+#define MAYBE_RECORD_WATCH_TIME(uma_name, watch_time)                  \
+  if (player_info.watch_time_info.watch_time != media::kNoTimestamp) { \
+    UMA_HISTOGRAM_LONG_TIMES(media::WatchTimeReporter::uma_name,       \
+                             player_info.watch_time_info.watch_time);  \
+  }
+
+  MAYBE_RECORD_WATCH_TIME(kHistogramAudioVideoAll, all_watch_time);
+  MAYBE_RECORD_WATCH_TIME(kHistogramAudioVideoMse, mse_watch_time);
+  MAYBE_RECORD_WATCH_TIME(kHistogramAudioVideoEme, eme_watch_time);
+  MAYBE_RECORD_WATCH_TIME(kHistogramAudioVideoSrc, src_watch_time);
+  MAYBE_RECORD_WATCH_TIME(kHistogramAudioVideoBattery, battery_watch_time);
+  MAYBE_RECORD_WATCH_TIME(kHistogramAudioVideoAc, ac_watch_time);
+#undef MAYBE_RECORD_WATCH_TIME
 }
 
 void MediaInternals::MediaInternalsUMAHandler::OnProcessTerminated(
@@ -529,13 +596,15 @@ void MediaInternals::OnMediaEvents(
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   // Notify observers that |event| has occurred.
   for (const auto& event : events) {
-    if (CanUpdate()) {
-      base::string16 update;
-      if (ConvertEventToUpdate(render_process_id, event, &update))
-        SendUpdate(update);
+    // Some events should not be recorded in the UI.
+    if (event.type != media::MediaLogEvent::Type::WATCH_TIME_UPDATE) {
+      if (CanUpdate()) {
+        base::string16 update;
+        if (ConvertEventToUpdate(render_process_id, event, &update))
+          SendUpdate(update);
+      }
+      SaveEvent(render_process_id, event);
     }
-
-    SaveEvent(render_process_id, event);
     uma_handler_->SavePlayerState(render_process_id, event);
   }
 }