[Chromecast] Fix pending push tracking in CmaAudioOutputStream

Bug: internal b/140603369
Change-Id: I188c969198078afb251c488fb0574a628dc8a2be
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1866973
Commit-Queue: Kenneth MacKay <kmackay@chromium.org>
Reviewed-by: Yuchen Liu <yucliu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#707016}

chromecast/media/audio/cast_audio_output_stream_unittest.cc

@@ -519,11 +519,8 @@ TEST_F(CastAudioOutputStreamTest, StartStopStart) {
   ASSERT_TRUE(stream->Open());
   RunThreadsUntilIdle();
 
-  // Set to busy, so that the OnPushBufferComplete callback is not called after
-  // the backend is stopped.
   FakeAudioDecoder* audio_decoder = GetAudioDecoder();
   ASSERT_TRUE(audio_decoder);
-  audio_decoder->set_pipeline_status(FakeAudioDecoder::PIPELINE_STATUS_BUSY);
 
   ::media::MockAudioSourceCallback source_callback;
   EXPECT_CALL(source_callback, OnMoreData(_, _, _, _))
@@ -531,8 +528,13 @@ TEST_F(CastAudioOutputStreamTest, StartStopStart) {
   stream->Start(&source_callback);
   RunThreadsUntilIdle();
   stream->Stop();
+  EXPECT_CALL(source_callback, OnMoreData(_, _, _, _)).Times(0);
+  RunThreadsUntilIdle();
+  testing::Mock::VerifyAndClearExpectations(&source_callback);
 
   // Ensure we fetch new data when restarting.
+  EXPECT_CALL(source_callback, OnMoreData(_, _, _, _))
+      .WillRepeatedly(Invoke(OnMoreData));
   int last_on_more_data_call_count = on_more_data_call_count_;
   stream->Start(&source_callback);
   RunThreadsUntilIdle();
@@ -551,8 +553,6 @@ TEST_F(CastAudioOutputStreamTest, StopPreventsCallbacks) {
   ASSERT_TRUE(stream->Open());
   RunThreadsUntilIdle();
 
-  // Set to busy, so that the OnPushBufferComplete callback is not called after
-  // the backend is stopped.
   FakeAudioDecoder* audio_decoder = GetAudioDecoder();
   ASSERT_TRUE(audio_decoder);
 

chromecast/media/audio/cma_audio_output_stream.cc

@@ -146,7 +146,6 @@ void CmaAudioOutputStream::Start(
   }
 
   if (!push_in_progress_) {
-    push_in_progress_ = true;
     PushBuffer();
   }
 }
@@ -161,7 +160,6 @@ void CmaAudioOutputStream::Stop(base::WaitableEvent* finished) {
     cma_backend_->Pause();
     cma_backend_state_ = CmaBackendState::kPaused;
   }
-  push_in_progress_ = false;
   source_callback_ = nullptr;
   finished->Signal();
 }
@@ -218,6 +216,7 @@ void CmaAudioOutputStream::PushBuffer() {
   // prevent the source callback from closing the output stream
   // mid-push.
   base::AutoLock lock(running_lock_);
+  DCHECK(!push_in_progress_);
 
   // Do not fill more buffers if we have stopped running.
   if (!running_)
@@ -227,10 +226,8 @@ void CmaAudioOutputStream::PushBuffer() {
   // Return quickly if so.
   if (!source_callback_ || encountered_error_ ||
       cma_backend_state_ != CmaBackendState::kStarted) {
-    push_in_progress_ = false;
     return;
   }
-  DCHECK(push_in_progress_);
 
   CmaBackend::AudioDecoder::RenderingDelay rendering_delay =
       audio_decoder_->GetRenderingDelay();
@@ -271,6 +268,7 @@ void CmaAudioOutputStream::PushBuffer() {
   decoder_buffer->set_timestamp(timestamp_helper_.GetTimestamp());
   timestamp_helper_.AddFrames(frame_count);
 
+  push_in_progress_ = true;
   BufferStatus status = audio_decoder_->PushBuffer(std::move(decoder_buffer));
   if (status != CmaBackend::BufferStatus::kBufferPending)
     OnPushBufferComplete(status);
@@ -316,7 +314,6 @@ void CmaAudioOutputStream::OnPushBufferComplete(BufferStatus status) {
            << " delay=" << delay << " buffer_duration_=" << buffer_duration_;
 
   push_timer_.Start(FROM_HERE, delay, this, &CmaAudioOutputStream::PushBuffer);
-  push_in_progress_ = true;
 }
 
 void CmaAudioOutputStream::OnDecoderError() {