[GRC] Add UKM report for background tabs audibility.

This patch adds UKM reports for background tabs audibility. Currently we
collect audible signal at frame-level, both main frame and child frames
are using the same source id to report UKM.

BUG=731270, 753486

Change-Id: I461ea2d8a6ef742fcb2850250ad68a5b71c89600
Reviewed-on: https://chromium-review.googlesource.com/604515
Commit-Queue: lpy <lpy@chromium.org>
Reviewed-by: Chris Hamilton <chrisha@chromium.org>
Reviewed-by: Oystein Eftevaag <oysteine@chromium.org>
Reviewed-by: Zhen Wang <zhenw@chromium.org>
Reviewed-by: Steven Holte <holte@chromium.org>
Cr-Commit-Position: refs/heads/master@{#496491}

services/resource_coordinator/coordination_unit/metrics_collector.cc

@@ -104,13 +104,23 @@ void MetricsCollector::OnFramePropertyChanged(
     if (frame_data.last_audible_time + kMaxAudioSlientTime < now) {
       MetricsReportRecord& record =
           metrics_report_record_map_[web_contents_cu->id()];
+      auto duration =
+          now -
+          web_contents_data_map_[web_contents_cu->id()].last_invisible_time;
+
       if (!record.first_audible_after_backgrounded_reported) {
-        const WebContentsData& web_contents_data =
-            web_contents_data_map_[web_contents_cu->id()];
         HEURISTICS_HISTOGRAM(kTabFromBackgroundedToFirstAudioStartsUMA,
-                             now - web_contents_data.last_invisible_time);
+                             duration);
         record.first_audible_after_backgrounded_reported = true;
       }
+
+      bool is_main_frame = frame_cu->IsMainFrame();
+      ReportAudibilityUKMIfNeeded(
+          web_contents_cu,
+          is_main_frame
+              ? &record.main_frame_first_audible_after_backgrounded_reported
+              : &record.child_frame_first_audible_after_backgrounded_reported,
+          is_main_frame, duration);
     }
   }
 }
@@ -239,6 +249,25 @@ void MetricsCollector::RecordCPUUsageForUkm(
       .Record(coordination_unit_manager().ukm_recorder());
 }
 
+void MetricsCollector::ReportAudibilityUKMIfNeeded(
+    const WebContentsCoordinationUnitImpl* web_contents_cu,
+    bool* reported,
+    bool is_main_frame,
+    base::TimeDelta duration) {
+  if (*reported)
+    return;
+  int64_t ukm_source_id = -1;
+  if (!web_contents_cu->GetProperty(mojom::PropertyType::kUKMSourceId,
+                                    &ukm_source_id)) {
+    return;
+  }
+  ukm::builders::TabManager_Background_FirstAudioStarts(ukm_source_id)
+      .SetIsMainFrame(is_main_frame)
+      .SetTimeFromBackgrounded(duration.InMilliseconds())
+      .Record(coordination_unit_manager().ukm_recorder());
+  *reported = true;
+}
+
 void MetricsCollector::UpdateUkmSourceIdForWebContents(
     const CoordinationUnitID& web_contents_cu_id,
     ukm::SourceId ukm_source_id) {
@@ -273,7 +302,9 @@ MetricsCollector::MetricsReportRecord::MetricsReportRecord()
       first_favicon_updated_after_backgrounded_reported(false),
       first_non_persistent_notification_created_after_backgrounded_reported(
           false),
-      first_title_updated_after_backgrounded_reported(false) {}
+      first_title_updated_after_backgrounded_reported(false),
+      main_frame_first_audible_after_backgrounded_reported(false),
+      child_frame_first_audible_after_backgrounded_reported(false) {}
 
 void MetricsCollector::MetricsReportRecord::Reset() {
   first_alert_fired_after_backgrounded_reported = false;
@@ -281,6 +312,8 @@ void MetricsCollector::MetricsReportRecord::Reset() {
   first_favicon_updated_after_backgrounded_reported = false;
   first_non_persistent_notification_created_after_backgrounded_reported = false;
   first_title_updated_after_backgrounded_reported = false;
+  main_frame_first_audible_after_backgrounded_reported = false;
+  child_frame_first_audible_after_backgrounded_reported = false;
 }
 
 }  // namespace resource_coordinator

services/resource_coordinator/coordination_unit/metrics_collector.h

@@ -54,11 +54,16 @@ class MetricsCollector : public CoordinationUnitGraphObserver {
   struct MetricsReportRecord {
     MetricsReportRecord();
     void Reset();
+    // UMA histograms report.
     bool first_alert_fired_after_backgrounded_reported;
     bool first_audible_after_backgrounded_reported;
     bool first_favicon_updated_after_backgrounded_reported;
     bool first_non_persistent_notification_created_after_backgrounded_reported;
     bool first_title_updated_after_backgrounded_reported;
+
+    // UKM collection report.
+    bool main_frame_first_audible_after_backgrounded_reported;
+    bool child_frame_first_audible_after_backgrounded_reported;
   };
 
   struct FrameData {
@@ -80,6 +85,11 @@ class MetricsCollector : public CoordinationUnitGraphObserver {
   void RecordCPUUsageForUkm(const CoordinationUnitID& web_contents_cu_id,
                             double cpu_usage,
                             size_t num_coresident_tabs);
+  void ReportAudibilityUKMIfNeeded(
+      const WebContentsCoordinationUnitImpl* web_contents_cu,
+      bool* reported,
+      bool is_main_frame,
+      base::TimeDelta duration);
   void UpdateUkmSourceIdForWebContents(
       const CoordinationUnitID& web_contents_cu_id,
       ukm::SourceId ukm_source_id);

tools/metrics/ukm/ukm.xml

@@ -1086,4 +1086,24 @@ be describing additional metrics about the same event.
   </metric>
 </event>
 
+<event name="TabManager.Background.FirstAudioStarts">
+  <owner>chrisha@chromium.org</owner>
+  <owner>lpy@chromium.org</owner>
+  <summary>
+    Collects the duration in MS from when the tab is backgrounded to when audio
+    starts to play. Only recorded when the tab is in the background.
+  </summary>
+  <metric name="IsMainFrame">
+    <summary>
+      Indicates whether the the audio stream belongs to the main frame.
+    </summary>
+  </metric>
+  <metric name="TimeFromBackgrounded">
+    <summary>
+      Duration in MS from when the tab is backgrounded to when audio starts to
+      play. Only recorded when the tab is in the background.
+    </summary>
+  </metric>
+</event>
+
 </ukm-configuration>