Add playback underflow logic to media::VideoRendererImpl.

BUG=144683

Review URL: https://codereview.chromium.org/391023002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@283501 0039d316-1c4b-4281-b951-d872f2087c98

media/filters/video_renderer_impl.cc

@@ -221,9 +221,15 @@ void VideoRendererImpl::ThreadMain() {
 
     // Remain idle until we have the next frame ready for rendering.
     if (ready_frames_.empty()) {
-      if (received_end_of_stream_ && !rendered_end_of_stream_) {
-        rendered_end_of_stream_ = true;
-        ended_cb_.Run();
+      if (received_end_of_stream_) {
+        if (!rendered_end_of_stream_) {
+          rendered_end_of_stream_ = true;
+          ended_cb_.Run();
+        }
+      } else {
+        buffering_state_ = BUFFERING_HAVE_NOTHING;
+        task_runner_->PostTask(
+            FROM_HERE, base::Bind(buffering_state_cb_, BUFFERING_HAVE_NOTHING));
       }
 
       UpdateStatsAndWait_Locked(kIdleTimeDelta);

media/filters/video_renderer_impl_unittest.cc

@@ -421,7 +421,7 @@ TEST_F(VideoRendererImplTest, FlushWithNothingBuffered) {
 
 TEST_F(VideoRendererImplTest, EndOfStream_ClipDuration) {
   Initialize();
-  QueueFrames("0 10 20 30");
+  QueueFrames("0");
   EXPECT_CALL(mock_cb_, Display(HasTimestamp(0)));
   EXPECT_CALL(mock_cb_, BufferingStateChange(BUFFERING_HAVE_ENOUGH));
   StartPlayingFrom(0);
@@ -497,8 +497,12 @@ TEST_F(VideoRendererImplTest, StartPlayingFrom_LowDelay) {
   InitializeWithLowDelay(true);
   QueueFrames("0");
 
+  // Expect to frequently have enough/nothing due to only requiring one frame.
   EXPECT_CALL(mock_cb_, Display(HasTimestamp(0)));
-  EXPECT_CALL(mock_cb_, BufferingStateChange(BUFFERING_HAVE_ENOUGH));
+  EXPECT_CALL(mock_cb_, BufferingStateChange(BUFFERING_HAVE_ENOUGH))
+      .Times(AtLeast(1));
+  EXPECT_CALL(mock_cb_, BufferingStateChange(BUFFERING_HAVE_NOTHING))
+      .Times(AtLeast(1));
   StartPlayingFrom(0);
 
   QueueFrames("10");
@@ -547,4 +551,35 @@ TEST_F(VideoRendererImplTest, VideoDecoder_InitFailure) {
   Stop();
 }
 
+TEST_F(VideoRendererImplTest, Underflow) {
+  Initialize();
+  QueueFrames("0 10 20 30");
+  EXPECT_CALL(mock_cb_, Display(HasTimestamp(0)));
+  EXPECT_CALL(mock_cb_, BufferingStateChange(BUFFERING_HAVE_ENOUGH));
+  StartPlayingFrom(0);
+
+  // Frames should be dropped and we should signal having nothing.
+  {
+    SCOPED_TRACE("Waiting for BUFFERING_HAVE_NOTHING");
+    WaitableMessageLoopEvent event;
+    EXPECT_CALL(mock_cb_, BufferingStateChange(BUFFERING_HAVE_NOTHING))
+        .WillOnce(RunClosure(event.GetClosure()));
+    AdvanceTimeInMs(100);
+    event.RunAndWait();
+  }
+
+  // Receiving end of stream should signal having enough.
+  {
+    SCOPED_TRACE("Waiting for BUFFERING_HAVE_ENOUGH");
+    WaitableMessageLoopEvent event;
+    EXPECT_CALL(mock_cb_, BufferingStateChange(BUFFERING_HAVE_ENOUGH))
+        .WillOnce(RunClosure(event.GetClosure()));
+    SatisfyPendingReadWithEndOfStream();
+    event.RunAndWait();
+  }
+
+  WaitForEnded();
+  Shutdown();
+}
+
 }  // namespace media