Reland: Make more media APIs aware of |delay| and |delay_timestamp|

media/audio/audio_output_device.cc

Index: media/audio/audio_output_device.cc
diff --git a/media/audio/audio_output_device.cc b/media/audio/audio_output_device.cc
index 0dcc76aca062b19bbdfb941088d053c1d1970ad3..e0ecc0f2a1d1a645f5f7f0b49fd76404c86221d7 100644
--- a/media/audio/audio_output_device.cc
+++ b/media/audio/audio_output_device.cc
@@ -39,14 +39,13 @@ class AudioOutputDevice::AudioThreadCallback
   void MapSharedMemory() override;
 
   // Called whenever we receive notifications about pending data.
-  void Process(uint32_t pending_data) override;
+  void Process(uint32_t control_signal) override;
 
   // Returns whether the current thread is the audio device thread or not.
   // Will always return true if DCHECKs are not enabled.
   bool CurrentThreadIsAudioDeviceThread();
 
  private:
-  const int bytes_per_frame_;
   AudioRendererSink::RenderCallback* render_callback_;
   std::unique_ptr<AudioBus> output_bus_;
   uint64_t callback_num_;
@@ -431,7 +430,6 @@ AudioOutputDevice::AudioThreadCallback::AudioThreadCallback(
     int memory_length,
     AudioRendererSink::RenderCallback* render_callback)
     : AudioDeviceThread::Callback(audio_parameters, memory, memory_length, 1),
-      bytes_per_frame_(audio_parameters.GetBytesPerFrame()),
       render_callback_(render_callback),
       callback_num_(0) {}
 
@@ -451,10 +449,7 @@ void AudioOutputDevice::AudioThreadCallback::MapSharedMemory() {
 }
 
 // Called whenever we receive notifications about pending data.
-void AudioOutputDevice::AudioThreadCallback::Process(uint32_t pending_data) {
-  // Convert the number of pending bytes in the render buffer into frames.
-  double frames_delayed = static_cast<double>(pending_data) / bytes_per_frame_;
-
+void AudioOutputDevice::AudioThreadCallback::Process(uint32_t control_signal) {
   callback_num_++;
   TRACE_EVENT1("audio", "AudioOutputDevice::FireRenderCallback",
                "callback_num", callback_num_);
@@ -472,16 +467,24 @@ void AudioOutputDevice::AudioThreadCallback::Process(uint32_t pending_data) {
   uint32_t frames_skipped = buffer->params.frames_skipped;
   buffer->params.frames_skipped = 0;
 
-  DVLOG(4) << __func__ << " pending_data:" << pending_data
-           << " frames_delayed(pre-round):" << frames_delayed
+  base::TimeDelta delay =
+      base::TimeDelta::FromMicroseconds(buffer->params.delay);
+  buffer->params.delay = 0;

[DaleCurtis, 2016/11/28 22:55:46]

Why?

[Mikhail, 2016/11/29 14:54:49]

took after 'frames_skipped' pattern, but now I see assigning delay and timestamp
to zero does not make much sense. I'll remove it. Thanks for
noticing!(alternatively syncreader could check that these params are zeroed i.e.
have been read, but not sure if it brings any benefit..)

+
+  base::TimeTicks delay_timestamp =
+      base::TimeTicks() +
+      base::TimeDelta::FromMicroseconds(buffer->params.delay_timestamp);
+  buffer->params.delay_timestamp = 0;

[DaleCurtis, 2016/11/28 22:55:46]

Ditto?

[Mikhail, 2016/11/29 14:54:49]

Done.

+
+  DVLOG(4) << __func__ << " delay:" << delay << " delay_timestamp:" << delay
            << " frames_skipped:" << frames_skipped;
 
   // Update the audio-delay measurement, inform about the number of skipped
   // frames, and ask client to render audio.  Since |output_bus_| is wrapping
   // the shared memory the Render() call is writing directly into the shared
   // memory.
-  render_callback_->Render(output_bus_.get(), std::round(frames_delayed),
-                           frames_skipped);
+  render_callback_->Render(delay, delay_timestamp, frames_skipped,
+                           output_bus_.get());
 }
 
 bool AudioOutputDevice::AudioThreadCallback::