Freeze media time and audio rendering when the system suspends.

media/renderers/audio_renderer_impl_unittest.cc

Index: media/renderers/audio_renderer_impl_unittest.cc
diff --git a/media/renderers/audio_renderer_impl_unittest.cc b/media/renderers/audio_renderer_impl_unittest.cc
index 04b728bf73806d940f27a3514e885ee8a5a51d33..e14de778af3dc99424be2c55ffdef88b647f1c68 100644
--- a/media/renderers/audio_renderer_impl_unittest.cc
+++ b/media/renderers/audio_renderer_impl_unittest.cc
@@ -748,6 +748,33 @@ TEST_F(AudioRendererImplTest, RenderingDelayedForEarlyStartTime) {
     ASSERT_NE(0.0f, bus->channel(0)[i]);
 }
 
+TEST_F(AudioRendererImplTest, RenderingDelayedForSuspend) {
+  Initialize();
+  Preroll(base::TimeDelta(), base::TimeDelta(), PIPELINE_OK);
+  StartTicking();
+
+  // Verify the first buffer is real data.
+  int frames_read = 0;
+  std::unique_ptr<AudioBus> bus = AudioBus::Create(hardware_params_);
+  EXPECT_TRUE(sink_->Render(bus.get(), 0, &frames_read));
+  EXPECT_NE(0, frames_read);
+  for (int i = 0; i < bus->frames(); ++i)
+    ASSERT_NE(0.0f, bus->channel(0)[i]);
+
+  // Verify after suspend we get silence.
+  renderer_->OnSuspend();

[xhwang, 2016/06/17 07:12:52]

Can you actually use TestPowerMonitorSource so we are closer to the real use
case? e.g.

https://cs.chromium.org/chromium/src/net/url_request/url_request_unittest.cc?...

+  EXPECT_TRUE(sink_->Render(bus.get(), 0, &frames_read));
+  EXPECT_EQ(0, frames_read);
+
+  // Verify after resume we get audio.
+  bus->Zero();
+  renderer_->OnResume();
+  EXPECT_TRUE(sink_->Render(bus.get(), 0, &frames_read));
+  EXPECT_NE(0, frames_read);
+  for (int i = 0; i < bus->frames(); ++i)
+    ASSERT_NE(0.0f, bus->channel(0)[i]);
+}
+
 TEST_F(AudioRendererImplTest, RenderingDelayDoesNotOverflow) {
   Initialize();
 
@@ -859,6 +886,16 @@ TEST_F(AudioRendererImplTest, TimeSourceBehavior) {
             ConvertMediaTime(base::TimeDelta(), &is_time_moving));
   EXPECT_TRUE(is_time_moving);
 
+  // A system suspend should freeze the time state and resume restart it.
+  renderer_->OnSuspend();
+  EXPECT_EQ(tick_clock_->NowTicks(),
+            ConvertMediaTime(base::TimeDelta(), &is_time_moving));
+  EXPECT_FALSE(is_time_moving);
+  renderer_->OnResume();
+  EXPECT_EQ(tick_clock_->NowTicks(),
+            ConvertMediaTime(base::TimeDelta(), &is_time_moving));
+  EXPECT_TRUE(is_time_moving);
+
   // Consume some more audio data.
   frames_to_consume = frames_buffered();
   tick_clock_->Advance(