Added metrics for background video playback.

content/renderer/media/renderer_webmediaplayer_delegate_browsertest.cc

Index: content/renderer/media/renderer_webmediaplayer_delegate_browsertest.cc
diff --git a/content/renderer/media/renderer_webmediaplayer_delegate_browsertest.cc b/content/renderer/media/renderer_webmediaplayer_delegate_browsertest.cc
index 060f391c23f6fedd020e612b72cfd099ad2e480f..2f29ce48c6c7a1d1be9e86b7225e763877710e28 100644
--- a/content/renderer/media/renderer_webmediaplayer_delegate_browsertest.cc
+++ b/content/renderer/media/renderer_webmediaplayer_delegate_browsertest.cc
@@ -7,8 +7,11 @@
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/location.h"
+#include "base/power_monitor/power_monitor.h"
+#include "base/power_monitor/power_monitor_source.h"
 #include "base/run_loop.h"
 #include "base/single_thread_task_runner.h"
+#include "base/test/histogram_tester.h"
 #include "base/test/simple_test_tick_clock.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "content/common/media/media_player_delegate_messages.h"
@@ -40,6 +43,21 @@ class MockWebMediaPlayerDelegateObserver
   MOCK_METHOD1(OnVolumeMultiplierUpdate, void(double));
 };
 
+class DummyPowerMonitorSource : public base::PowerMonitorSource {
+ public:
+  DummyPowerMonitorSource() {}
+  ~DummyPowerMonitorSource() override {}

[mlamouri (slow - plz ping), 2016/08/08 13:19:31]

nit: `= default;` FTW

+
+  void Suspend() { ProcessPowerEvent(SUSPEND_EVENT); }
+  void Resume() { ProcessPowerEvent(RESUME_EVENT); }
+
+ private:
+  // base::PowerMonitorSource implementation.
+  bool IsOnBatteryPowerImpl() override { return false; }
+
+  DISALLOW_COPY_AND_ASSIGN(DummyPowerMonitorSource);
+};
+
 class RendererWebMediaPlayerDelegateTest : public content::RenderViewTest {
  public:
   RendererWebMediaPlayerDelegateTest() {}
@@ -47,6 +65,10 @@ class RendererWebMediaPlayerDelegateTest : public content::RenderViewTest {
 
   void SetUp() override {
     RenderViewTest::SetUp();
+
+    power_monitor_source_ = new DummyPowerMonitorSource();
+    power_monitor_.reset(new base::PowerMonitor(
+        base::WrapUnique(power_monitor_source_)));
     delegate_manager_.reset(
         new RendererWebMediaPlayerDelegate(view_->GetMainRenderFrame()));
   }
@@ -55,6 +77,7 @@ class RendererWebMediaPlayerDelegateTest : public content::RenderViewTest {
     // Destruct the controller prior to any other tear down to avoid out of
     // order destruction relative to the test render frame.
     delegate_manager_.reset();
+    power_monitor_.reset();
     RenderViewTest::TearDown();
   }
 
@@ -77,6 +100,16 @@ class RendererWebMediaPlayerDelegateTest : public content::RenderViewTest {
     delegate_manager_->OnMediaDelegatePause(delegate_id);
   }
 
+  void CallSetIsPlayingBackgroundVideo(bool is_playing) {
+    delegate_manager_->SetIsPlayingBackgroundVideo(is_playing);
+  }
+
+  base::TimeTicks GetBackgroundVideoPlayingStartTime() {
+    return delegate_manager_->background_video_playing_start_time_;
+  }
+
+  DummyPowerMonitorSource* power_monitor_source_ = nullptr;
+  std::unique_ptr<base::PowerMonitor> power_monitor_;
   std::unique_ptr<RendererWebMediaPlayerDelegate> delegate_manager_;
 
  private:
@@ -366,5 +399,47 @@ TEST_F(RendererWebMediaPlayerDelegateTest, IsPlayingBackgroundVideo) {
   EXPECT_NE(old_value, delegate_manager_->IsPlayingBackgroundVideo());
 }
 
+TEST_F(RendererWebMediaPlayerDelegateTest, Histograms) {
+  MockWebMediaPlayerDelegateObserver observer;
+  int delegate_id = delegate_manager_->AddObserver(&observer);
+  base::HistogramTester histogram_tester;
+  histogram_tester.ExpectTotalCount("Media.Session.BackgroundTime", 0);
+
+  // Pausing or showing doesn't record anything as background playback
+  // hasn't started yet.
+  delegate_manager_->DidPlay(
+      delegate_id, true, true, false, base::TimeDelta());
+  CallOnMediaDelegatePause(delegate_id);
+  histogram_tester.ExpectTotalCount("Media.Session.BackgroundTime", 0);
+
+  delegate_manager_->DidPlay(
+      delegate_id, true, true, false, base::TimeDelta());
+  delegate_manager_->WasShown();
+  histogram_tester.ExpectTotalCount("Media.Session.BackgroundTime", 0);
+
+  // Doing this things after the background playback has started should record
+  // the time.
+  delegate_manager_->DidPlay(
+      delegate_id, true, true, false, base::TimeDelta());
+  SetPlayingBackgroundVideo(true);
+  CallOnMediaDelegatePause(delegate_id);
+  histogram_tester.ExpectTotalCount("Media.Session.BackgroundTime", 1);
+
+  delegate_manager_->DidPlay(
+      delegate_id, true, true, false, base::TimeDelta());
+  SetPlayingBackgroundVideo(true);
+  delegate_manager_->WasShown();
+  histogram_tester.ExpectTotalCount("Media.Session.BackgroundTime", 2);
+}
+
+TEST_F(RendererWebMediaPlayerDelegateTest, PowerObserver) {
+  CallSetIsPlayingBackgroundVideo(true);
+  base::TimeTicks time_before_suspend = GetBackgroundVideoPlayingStartTime();
+
+  power_monitor_source_->Suspend();
+  power_monitor_source_->Resume();
+
+  EXPECT_GE(GetBackgroundVideoPlayingStartTime(), time_before_suspend);
+}
 
 }  // namespace media