Caching AudioOutputDevice instances in mixer manager

media/audio/clockless_audio_sink.cc

 // Copyright 2013 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/audio/clockless_audio_sink.h"
 
 #include "base/bind.h"
 #include "base/location.h"
 #include "base/single_thread_task_runner.h"
 #include "base/threading/simple_thread.h"
@@ skipping 57 matching lines @@
 
   AudioRendererSink::RenderCallback* callback_;
   std::unique_ptr<AudioBus> audio_bus_;
   std::unique_ptr<base::WaitableEvent> stop_event_;
   std::unique_ptr<base::DelegateSimpleThread> thread_;
   base::TimeDelta playback_time_;
   std::unique_ptr<AudioHash> audio_hash_;
 };
 
 ClocklessAudioSink::ClocklessAudioSink()
-    : initialized_(false), playing_(false), hashing_(false) {}
+    : ClocklessAudioSink(OutputDeviceInfo()) {}
+
+ClocklessAudioSink::ClocklessAudioSink(const OutputDeviceInfo& device_info)
+    : device_info_(device_info),
+      initialized_(false),
+      playing_(false),
+      hashing_(false) {}
 
 ClocklessAudioSink::~ClocklessAudioSink() {}
 
 void ClocklessAudioSink::Initialize(const AudioParameters& params,
                                     RenderCallback* callback) {
   DCHECK(!initialized_);
   thread_.reset(new ClocklessAudioSinkThread(params, callback, hashing_));
   initialized_ = true;
 }
 
@@ skipping 26 matching lines @@
   playing_ = false;
   playback_time_ = thread_->Stop();
 }
 
 bool ClocklessAudioSink::SetVolume(double volume) {
   // Audio is always muted.
   return volume == 0.0;
 }
 
 OutputDeviceInfo ClocklessAudioSink::GetOutputDeviceInfo() {
-  return OutputDeviceInfo();
+  return device_info_;
 }
 
 void ClocklessAudioSink::StartAudioHashForTesting() {
   DCHECK(!initialized_);
   hashing_ = true;
 }
 
 std::string ClocklessAudioSink::GetAudioHashForTesting() {
   return thread_ && hashing_ ? thread_->GetAudioHash() : std::string();
 }
 
 }  // namespace media