Make media::AudioRenderer inherit from media::TimeSource.

media/filters/audio_renderer_impl.cc

Index: media/filters/audio_renderer_impl.cc
diff --git a/media/filters/audio_renderer_impl.cc b/media/filters/audio_renderer_impl.cc
index 9b0c098b191ecbdfae2fa85e03c60f2f855aed0b..49ceb51c36ecd1a61afdede43a0cd9bd272798d8 100644
--- a/media/filters/audio_renderer_impl.cc
+++ b/media/filters/audio_renderer_impl.cc
@@ -14,6 +14,7 @@
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/single_thread_task_runner.h"
+#include "base/time/default_tick_clock.h"
 #include "media/base/audio_buffer.h"
 #include "media/base/audio_buffer_converter.h"
 #include "media/base/audio_hardware_config.h"
@@ -52,6 +53,7 @@ AudioRendererImpl::AudioRendererImpl(
                                                  decoders.Pass(),
                                                  set_decryptor_ready_cb)),
       hardware_config_(hardware_config),
+      tick_clock_(new base::DefaultTickClock()),
       state_(kUninitialized),
       buffering_state_(BUFFERING_HAVE_NOTHING),
       rendering_(false),
@@ -72,7 +74,7 @@ AudioRendererImpl::~AudioRendererImpl() {
   DCHECK(!algorithm_.get());
 }
 
-void AudioRendererImpl::StartRendering() {
+void AudioRendererImpl::StartTicking() {
   DVLOG(1) << __FUNCTION__;
   DCHECK(task_runner_->BelongsToCurrentThread());
   DCHECK(!rendering_);
@@ -102,7 +104,7 @@ void AudioRendererImpl::StartRendering_Locked() {
   sink_->Play();
 }
 
-void AudioRendererImpl::StopRendering() {
+void AudioRendererImpl::StopTicking() {
   DVLOG(1) << __FUNCTION__;
   DCHECK(task_runner_->BelongsToCurrentThread());
   DCHECK(rendering_);
@@ -130,17 +132,6 @@ void AudioRendererImpl::StopRendering_Locked() {
   sink_->Pause();
 }
 
-void AudioRendererImpl::SetMediaTime(base::TimeDelta time) {
-  DVLOG(1) << __FUNCTION__ << "(" << time.InMicroseconds() << ")";
-  DCHECK(task_runner_->BelongsToCurrentThread());
-
-  base::AutoLock auto_lock(lock_);
-  DCHECK(!rendering_);
-  DCHECK_EQ(state_, kFlushed);
-
-  start_timestamp_ = time;
-}
-
 void AudioRendererImpl::Flush(const base::Closure& callback) {
   DVLOG(1) << __FUNCTION__;
   DCHECK(task_runner_->BelongsToCurrentThread());
@@ -244,6 +235,28 @@ void AudioRendererImpl::StartPlaying() {
   AttemptRead_Locked();
 }
 
+void AudioRendererImpl::SetMediaTime(base::TimeDelta timestamp) {
+  DVLOG(1) << __FUNCTION__ << "(" << timestamp.InMicroseconds() << ")";
+  DCHECK(task_runner_->BelongsToCurrentThread());
+
+  base::AutoLock auto_lock(lock_);
+  DCHECK(!rendering_);
+  DCHECK_EQ(state_, kFlushed);
+  start_timestamp_ = timestamp;
+}
+
+base::TimeDelta AudioRendererImpl::CurrentMediaTime() {
+  DVLOG(1) << __FUNCTION__;
+  DCHECK(task_runner_->BelongsToCurrentThread());
+
+  base::AutoLock auto_lock(lock_);
+  base::TimeDelta timestamp = audio_clock_->CurrentMediaTimestamp(
+      tick_clock_->NowTicks() - last_render_ticks_);
+  if (timestamp == kNoTimestamp())
+    return start_timestamp_;
+  return timestamp;
+}
+
 void AudioRendererImpl::Initialize(DemuxerStream* stream,
                                    const PipelineStatusCB& init_cb,
                                    const StatisticsCB& statistics_cb,
@@ -369,6 +382,11 @@ void AudioRendererImpl::SetVolume(float volume) {
   sink_->SetVolume(volume);
 }
 
+void AudioRendererImpl::SetTickClockForTesting(
+    scoped_ptr<base::TickClock> tick_clock) {
+  tick_clock_.swap(tick_clock);
+}
+
 void AudioRendererImpl::DecodedAudioReady(
     AudioBufferStream::Status status,
     const scoped_refptr<AudioBuffer>& buffer) {
@@ -565,6 +583,7 @@ int AudioRendererImpl::Render(AudioBus* audio_bus,
   base::Closure time_cb;
   {
     base::AutoLock auto_lock(lock_);
+    last_render_ticks_ = tick_clock_->NowTicks();
 
     // Ensure Stop() hasn't destroyed our |algorithm_| on the pipeline thread.
     if (!algorithm_) {