More tracing for audio rendering

media/base/audio_renderer_mixer.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "media/base/audio_renderer_mixer.h"
 
 #include <cmath>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
 #include "base/metrics/histogram_macros.h"
+#include "base/trace_event/trace_event.h"
 
 namespace media {
 
 enum { kPauseDelaySeconds = 10 };
 
 // Tracks the maximum value of a counter and logs it into a UMA histogram upon
 // each increase of the maximum. NOT thread-safe, make sure it is used under
 // lock.
 class AudioRendererMixer::UMAMaxValueTracker {
  public:
@@ skipping 133 matching lines @@
   return audio_sink_->GetOutputDeviceInfo();
 }
 
 bool AudioRendererMixer::CurrentThreadIsRenderingThread() {
   return audio_sink_->CurrentThreadIsRenderingThread();
 }
 
 int AudioRendererMixer::Render(AudioBus* audio_bus,
                                uint32_t frames_delayed,
                                uint32_t frames_skipped) {
+  TRACE_EVENT0("audio", "AudioRendererMixer::Render");
   base::AutoLock auto_lock(lock_);
 
   // If there are no mixer inputs and we haven't seen one for a while, pause the
   // sink to avoid wasting resources when media elements are present but remain
   // in the pause state.
   const base::TimeTicks now = base::TimeTicks::Now();
   if (!master_converter_.empty()) {
     last_play_time_ = now;
   } else if (now - last_play_time_ >= pause_delay_ && playing_) {
     audio_sink_->Pause();
     playing_ = false;
   }
 
   master_converter_.ConvertWithDelay(frames_delayed, audio_bus);
   return audio_bus->frames();
 }
 
 void AudioRendererMixer::OnRenderError() {
   // Call each mixer input and signal an error.
   base::AutoLock auto_lock(lock_);
   for (const auto& cb : error_callbacks_)
     cb.Run();
 }
 
 }  // namespace media