Switch Audio Preferences to per device.

Currently Chrome stores one global audio volume pref; if a user switches devices, this value remains the same. Change this so that we remember what volume (and mute setting) a user switched to when on a particular device, so when we switch to that device, we can set the volume/mute setting back to it again.

R=brettw@chromium.org, hshi@chromium.org, stevenjb@chromium.org
BUG=175798
TEST=Switched between speakers and USB headphones to verify that audio settings were rememebered and switched to correctly.

Review URL: https://codereview.chromium.org/14801002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@198011 0039d316-1c4b-4281-b951-d872f2087c98

14 files changed, 369 insertions, 29 deletions

diff --git a/chrome/browser/chromeos/audio/audio_devices_pref_handler_impl.cc b/chrome/browser/chromeos/audio/audio_devices_pref_handler_impl.cc
new file mode 100644
index 0000000..c8d5b03
--- /dev/null
+++ b/chrome/browser/chromeos/audio/audio_devices_pref_handler_impl.cc
@@ -0,0 +1,192 @@
+// Copyright (c) 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 "chrome/browser/chromeos/audio/audio_devices_pref_handler_impl.h"
+
+#include "base/bind.h"
+#include "base/bind_helpers.h"
+#include "base/logging.h"
+#include "base/prefs/pref_registry_simple.h"
+#include "base/prefs/pref_service.h"
+#include "base/strings/string_number_conversions.h"
+#include "chrome/browser/prefs/scoped_user_pref_update.h"
+#include "chrome/common/chrome_notification_types.h"
+#include "chrome/common/pref_names.h"
+#include "chromeos/audio/cras_audio_handler.h"
+
+namespace chromeos {
+
+namespace {
+
+// Default value for the volume pref, as a percent in the range [0.0, 100.0].
+const double kDefaultVolumePercent = 75.0;
+
+// Values used for muted preference.
+const int kPrefMuteOff = 0;
+const int kPrefMuteOn = 1;
+
+}  // namespace
+
+double AudioDevicesPrefHandlerImpl::GetOutputVolumeValue() {
+  if (!CrasAudioHandler::IsInitialized())
+    return kDefaultVolumePercent;
+
+  UpdateDevicesVolumePref();
+  std::string active_device_id = base::Uint64ToString(
+      CrasAudioHandler::Get()->GetActiveOutputNode());
+  if (!device_volume_settings_->HasKey(active_device_id))
+    MigrateDeviceVolumeSettings(active_device_id);
+  double volume = kDefaultVolumePercent;
+  device_volume_settings_->GetDouble(active_device_id, &volume);
+  return volume;
+}
+
+void AudioDevicesPrefHandlerImpl::SetOutputVolumeValue(double volume_percent) {
+  std::string active_device_id = base::Uint64ToString(
+      CrasAudioHandler::Get()->GetActiveOutputNode());
+  if (volume_percent > 100.0)
+    volume_percent = 100.0;
+  if (volume_percent < 0.0)
+    volume_percent = 0.0;
+  device_volume_settings_->SetDouble(active_device_id, volume_percent);
+  SaveDevicesVolumePref();
+}
+
+bool AudioDevicesPrefHandlerImpl::GetOutputMuteValue() {
+  if (!CrasAudioHandler::IsInitialized())
+    return false;
+
+  UpdateDevicesVolumePref();
+  std::string active_device_id = base::Uint64ToString(
+      CrasAudioHandler::Get()->GetActiveOutputNode());
+  if (!device_mute_settings_->HasKey(active_device_id))
+    MigrateDeviceMuteSettings(active_device_id);
+  int mute = kPrefMuteOff;
+  device_mute_settings_->GetInteger(active_device_id, &mute);
+  return (mute == kPrefMuteOn);
+}
+
+void AudioDevicesPrefHandlerImpl::SetOutputMuteValue(bool mute) {
+  std::string active_device_id = base::Uint64ToString(
+      CrasAudioHandler::Get()->GetActiveOutputNode());
+  device_mute_settings_->SetBoolean(active_device_id,
+                                   mute ? kPrefMuteOn : kPrefMuteOff);
+  SaveDevicesVolumePref();
+}
+
+bool AudioDevicesPrefHandlerImpl::GetAudioCaptureAllowedValue() {
+  return local_state_->GetBoolean(prefs::kAudioCaptureAllowed);
+}
+
+bool AudioDevicesPrefHandlerImpl::GetAudioOutputAllowedValue() {
+  return local_state_->GetBoolean(prefs::kAudioOutputAllowed);
+}
+
+void AudioDevicesPrefHandlerImpl::AddAudioPrefObserver(
+    AudioPrefObserver* observer) {
+  observers_.AddObserver(observer);
+}
+
+void AudioDevicesPrefHandlerImpl::RemoveAudioPrefObserver(
+    AudioPrefObserver* observer) {
+  observers_.RemoveObserver(observer);
+}
+
+AudioDevicesPrefHandlerImpl::AudioDevicesPrefHandlerImpl(
+    PrefService* local_state)
+    : device_mute_settings_(new base::DictionaryValue()),
+      device_volume_settings_(new base::DictionaryValue()),
+      local_state_(local_state) {
+  InitializePrefObservers();
+
+  UpdateDevicesMutePref();
+  UpdateDevicesVolumePref();
+}
+
+AudioDevicesPrefHandlerImpl::~AudioDevicesPrefHandlerImpl() {
+};
+
+void AudioDevicesPrefHandlerImpl::InitializePrefObservers() {
+  pref_change_registrar_.Init(local_state_);
+  base::Closure callback =
+      base::Bind(&AudioDevicesPrefHandlerImpl::NotifyAudioPolicyChange,
+                 base::Unretained(this));
+  pref_change_registrar_.Add(prefs::kAudioOutputAllowed, callback);
+  pref_change_registrar_.Add(prefs::kAudioCaptureAllowed, callback);
+}
+
+void AudioDevicesPrefHandlerImpl::UpdateDevicesMutePref() {
+  const base::DictionaryValue* mute_prefs =
+      local_state_->GetDictionary(prefs::kAudioDevicesMute);
+  if (mute_prefs)
+    device_mute_settings_.reset(mute_prefs->DeepCopy());
+}
+
+void AudioDevicesPrefHandlerImpl::SaveDevicesMutePref() {
+  DictionaryPrefUpdate dict_update(local_state_, prefs::kAudioDevicesMute);
+  base::DictionaryValue::Iterator it(*device_mute_settings_);
+  while (!it.IsAtEnd()) {
+    int mute = kPrefMuteOff;
+    it.value().GetAsInteger(&mute);
+    dict_update->Set(it.key(), new base::FundamentalValue(mute));
+    it.Advance();
+  }
+}
+
+void AudioDevicesPrefHandlerImpl::UpdateDevicesVolumePref() {
+  const base::DictionaryValue* volume_prefs =
+      local_state_->GetDictionary(prefs::kAudioDevicesVolumePercent);
+  if (volume_prefs)
+    device_volume_settings_.reset(volume_prefs->DeepCopy());
+}
+
+void AudioDevicesPrefHandlerImpl::SaveDevicesVolumePref() {
+  DictionaryPrefUpdate dict_update(local_state_,
+                                   prefs::kAudioDevicesVolumePercent);
+  base::DictionaryValue::Iterator it(*device_volume_settings_);
+  while (!it.IsAtEnd()) {
+    double volume = kDefaultVolumePercent;
+    it.value().GetAsDouble(&volume);
+    dict_update->Set(it.key(), new base::FundamentalValue(volume));
+    it.Advance();
+  }
+}
+
+void AudioDevicesPrefHandlerImpl::MigrateDeviceMuteSettings(
+    std::string active_device) {
+  int old_mute = local_state_->GetInteger(prefs::kAudioMute);
+  device_mute_settings_->SetInteger(active_device, old_mute);
+  SaveDevicesMutePref();
+}
+
+void AudioDevicesPrefHandlerImpl::MigrateDeviceVolumeSettings(
+    std::string active_device) {
+  double old_volume = local_state_->GetDouble(prefs::kAudioVolumePercent);
+  device_volume_settings_->SetDouble(active_device, old_volume);
+  SaveDevicesVolumePref();
+}
+
+void AudioDevicesPrefHandlerImpl::NotifyAudioPolicyChange() {
+  FOR_EACH_OBSERVER(AudioPrefObserver,
+                    observers_,
+                    OnAudioPolicyPrefChanged());
+}
+
+// static
+void AudioDevicesPrefHandlerImpl::RegisterPrefs(PrefRegistrySimple* registry) {
+  registry->RegisterDictionaryPref(prefs::kAudioDevicesVolumePercent);
+  registry->RegisterDictionaryPref(prefs::kAudioDevicesMute);
+
+  // TODO(jennyz,rkc): Move the rest of the preferences registered by
+  // AudioPrefHandlerImpl::RegisterPrefs here once we remove the old audio
+  // handler code.
+}
+
+// static
+AudioDevicesPrefHandler* AudioDevicesPrefHandler::Create(
+    PrefService* local_state) {
+  return new AudioDevicesPrefHandlerImpl(local_state);
+}
+
+}  // namespace chromeos
diff --git a/chrome/browser/chromeos/audio/audio_devices_pref_handler_impl.h b/chrome/browser/chromeos/audio/audio_devices_pref_handler_impl.h
new file mode 100644
index 0000000..44dafe5
--- /dev/null
+++ b/chrome/browser/chromeos/audio/audio_devices_pref_handler_impl.h
@@ -0,0 +1,74 @@
+// Copyright (c) 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.
+
+#ifndef CHROME_BROWSER_CHROMEOS_AUDIO_AUDIO_DEVICES_PREF_HANDLER_IMPL_H_
+#define CHROME_BROWSER_CHROMEOS_AUDIO_AUDIO_DEVICES_PREF_HANDLER_IMPL_H_
+
+#include "base/observer_list.h"
+#include "base/prefs/pref_change_registrar.h"
+#include "base/values.h"
+#include "chromeos/audio/audio_devices_pref_handler.h"
+
+class PrefRegistrySimple;
+class PrefService;
+
+namespace chromeos {
+
+// Class which implements AudioDevicesPrefHandler interface and register audio
+// preferences as well.
+class AudioDevicesPrefHandlerImpl : public AudioDevicesPrefHandler {
+ public:
+  explicit AudioDevicesPrefHandlerImpl(PrefService* local_state);
+
+  // Overridden from AudioDevicesPrefHandler.
+  virtual double GetOutputVolumeValue() OVERRIDE;
+  virtual bool GetOutputMuteValue() OVERRIDE;
+  virtual void SetOutputVolumeValue(double volume_percent) OVERRIDE;
+  virtual void SetOutputMuteValue(bool mute_on) OVERRIDE;
+  virtual bool GetAudioCaptureAllowedValue() OVERRIDE;
+  virtual bool GetAudioOutputAllowedValue() OVERRIDE;
+  virtual void AddAudioPrefObserver(AudioPrefObserver* observer) OVERRIDE;
+  virtual void RemoveAudioPrefObserver(AudioPrefObserver* observer) OVERRIDE;
+
+  // Registers volume and mute preferences.
+  static void RegisterPrefs(PrefRegistrySimple* registry);
+
+ protected:
+  virtual ~AudioDevicesPrefHandlerImpl();
+
+ private:
+  // Initializes the observers for the policy prefs.
+  void InitializePrefObservers();
+
+  // Update and save methods for the mute preferences for all devices.
+  void UpdateDevicesMutePref();
+  void SaveDevicesMutePref();
+
+  // Update and save methods for the volume preferences for all devices.
+  void UpdateDevicesVolumePref();
+  void SaveDevicesVolumePref();
+
+  // Methods to migrate the mute and volume settings for a device from the
+  // previous global pref value to the new per device pref value for the
+  // current active device. If a previous global setting doesn't exist, we'll
+  // use default values of mute = off and volume = 75%.
+  void MigrateDeviceMuteSettings(std::string active_device);
+  void MigrateDeviceVolumeSettings(std::string active_device);
+
+  // Notifies the AudioPrefObserver for audio policy pref changes.
+  void NotifyAudioPolicyChange();
+
+  scoped_ptr<base::DictionaryValue> device_mute_settings_;
+  scoped_ptr<base::DictionaryValue> device_volume_settings_;
+
+  PrefService* local_state_;  // not owned
+  PrefChangeRegistrar pref_change_registrar_;
+  ObserverList<AudioPrefObserver> observers_;
+
+  DISALLOW_COPY_AND_ASSIGN(AudioDevicesPrefHandlerImpl);
+};
+
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_AUDIO_AUDIO_DEVICES_PREF_HANDLER_IMPL_H_
diff --git a/chrome/browser/chromeos/audio/audio_pref_handler_impl.h b/chrome/browser/chromeos/audio/audio_pref_handler_impl.h
index 454180f..47f8da0 100644
--- a/chrome/browser/chromeos/audio/audio_pref_handler_impl.h
+++ b/chrome/browser/chromeos/audio/audio_pref_handler_impl.h
@@ -14,6 +14,8 @@ class PrefService;
 
 namespace chromeos {
 
+// TODO(jennyz,rkc): This class will be removed once we remove the old Audio
+// Handler code.
 // Class which implements AudioPrefHandler interface and register audio
 // preferences as well.
 class AudioPrefHandlerImpl : public AudioPrefHandler {
diff --git a/chrome/browser/chromeos/chrome_browser_main_chromeos.cc b/chrome/browser/chromeos/chrome_browser_main_chromeos.cc
index 1f395f1..3e570f1 100644
--- a/chrome/browser/chromeos/chrome_browser_main_chromeos.cc
+++ b/chrome/browser/chromeos/chrome_browser_main_chromeos.cc
@@ -91,6 +91,7 @@
 #include "chrome/common/chrome_version_info.h"
 #include "chrome/common/logging_chrome.h"
 #include "chrome/common/pref_names.h"
+#include "chromeos/audio/audio_devices_pref_handler.h"
 #include "chromeos/audio/audio_pref_handler.h"
 #include "chromeos/audio/cras_audio_handler.h"
 #include "chromeos/audio/cras_audio_switch_handler.h"
@@ -485,7 +486,7 @@ void ChromeBrowserMainPartsChromeos::PreMainMessageLoopRun() {
     CrasAudioSwitchHandler::Initialize();
   if (UseNewAudioHandler()) {
     CrasAudioHandler::Initialize(
-        AudioPrefHandler::Create(g_browser_process->local_state()));
+        AudioDevicesPrefHandler::Create(g_browser_process->local_state()));
   } else {
    AudioHandler::Initialize(
        AudioPrefHandler::Create(g_browser_process->local_state()));
diff --git a/chrome/browser/prefs/browser_prefs.cc b/chrome/browser/prefs/browser_prefs.cc
index 291c1cde..fac503e 100644
--- a/chrome/browser/prefs/browser_prefs.cc
+++ b/chrome/browser/prefs/browser_prefs.cc
@@ -117,6 +117,7 @@
 
 #if defined(OS_CHROMEOS)
 #include "chrome/browser/chromeos/app_mode/kiosk_app_manager.h"
+#include "chrome/browser/chromeos/audio/audio_devices_pref_handler_impl.h"
 #include "chrome/browser/chromeos/audio/audio_handler.h"
 #include "chrome/browser/chromeos/audio/audio_pref_handler_impl.h"
 #include "chrome/browser/chromeos/customization_document.h"
@@ -241,6 +242,7 @@ void RegisterLocalState(PrefRegistrySimple* registry) {
 #endif
 
 #if defined(OS_CHROMEOS)
+  chromeos::AudioDevicesPrefHandlerImpl::RegisterPrefs(registry);
   chromeos::AudioPrefHandlerImpl::RegisterPrefs(registry);
   chromeos::DataPromoNotification::RegisterPrefs(registry);
   chromeos::DeviceOAuth2TokenService::RegisterPrefs(registry);
diff --git a/chrome/chrome_browser_chromeos.gypi b/chrome/chrome_browser_chromeos.gypi
index 61bb92a..5fab399 100644
--- a/chrome/chrome_browser_chromeos.gypi
+++ b/chrome/chrome_browser_chromeos.gypi
@@ -134,6 +134,8 @@
         'browser/chromeos/attestation/attestation_ca_client.h',
         'browser/chromeos/attestation/attestation_policy_observer.cc',
         'browser/chromeos/attestation/attestation_policy_observer.h',
+        'browser/chromeos/audio/audio_devices_pref_handler_impl.cc',
+        'browser/chromeos/audio/audio_devices_pref_handler_impl.h',
         'browser/chromeos/audio/audio_handler.cc',
         'browser/chromeos/audio/audio_handler.h',
         'browser/chromeos/audio/audio_pref_handler_impl.cc',
diff --git a/chrome/common/pref_names.cc b/chrome/common/pref_names.cc
index 58a075b..1d2ce8e 100644
--- a/chrome/common/pref_names.cc
+++ b/chrome/common/pref_names.cc
@@ -541,12 +541,25 @@ const char kDefaultAppsInstallState[] = "default_apps_install_state";
 const char kHideWebStoreIcon[] = "hide_web_store_icon";
 
 #if defined(OS_CHROMEOS)
+// A dictionary pref to hold the mute setting for all the currently known
+// audio devices.
+const char kAudioDevicesMute[] = "settings.audio.devices.mute";
+
+// A dictionary pref storing the volume settings for all the currently known
+// audio devices.
+const char kAudioDevicesVolumePercent[] =
+    "settings.audio.devices.volume_percent";
+
 // An integer pref to initially mute volume if 1. This pref is ignored if
 // |kAudioOutputAllowed| is set to false, but its value is preserved, therefore
-// when the policy is lifted the original mute state is restored.
+// when the policy is lifted the original mute state is restored.  This setting
+// is here only for migration purposes now. It is being replaced by the
+// |kAudioDevicesMute| setting.
 const char kAudioMute[] = "settings.audio.mute";
 
-// A double pref storing the user-requested volume.
+// A double pref storing the user-requested volume. This setting is here only
+// for migration purposes now. It is being replaced by the
+// |kAudioDevicesVolumePercent| setting.
 const char kAudioVolumePercent[] = "settings.audio.volume_percent";
 
 // A boolean pref set to true if touchpad tap-to-click is enabled.
diff --git a/chrome/common/pref_names.h b/chrome/common/pref_names.h
index 8958e1b..985096d 100644
--- a/chrome/common/pref_names.h
+++ b/chrome/common/pref_names.h
@@ -205,6 +205,8 @@ extern const char kNetworkPredictionEnabled[];
 extern const char kDefaultAppsInstallState[];
 extern const char kHideWebStoreIcon[];
 #if defined(OS_CHROMEOS)
+extern const char kAudioDevicesMute[];
+extern const char kAudioDevicesVolumePercent[];
 extern const char kAudioMute[];
 extern const char kAudioVolumePercent[];
 extern const char kTapToClickEnabled[];
diff --git a/chromeos/audio/audio_devices_pref_handler.h b/chromeos/audio/audio_devices_pref_handler.h
new file mode 100644
index 0000000..63e3ed7
--- /dev/null
+++ b/chromeos/audio/audio_devices_pref_handler.h
@@ -0,0 +1,55 @@
+// Copyright (c) 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.
+
+#ifndef CHROMEOS_AUDIO_AUDIO_DEVICES_PREF_HANDLER_H_
+#define CHROMEOS_AUDIO_AUDIO_DEVICES_PREF_HANDLER_H_
+
+#include "base/basictypes.h"
+#include "base/memory/ref_counted.h"
+#include "chromeos/audio/audio_pref_observer.h"
+#include "chromeos/chromeos_export.h"
+
+class PrefRegistrySimple;
+
+namespace chromeos {
+
+// Interface that handles audio preference related work, reads and writes
+// audio preferences, and notifies AudioPrefObserver for audio preference
+// changes.
+class CHROMEOS_EXPORT AudioDevicesPrefHandler
+    : public base::RefCountedThreadSafe<AudioDevicesPrefHandler> {
+ public:
+  // Gets the audio output volume value from prefs for the active device.
+  virtual double GetOutputVolumeValue() = 0;
+  // Reads the audio output mute value from prefs for the active device.
+  virtual bool GetOutputMuteValue() = 0;
+
+  // Sets the output audio volume value to prefs for the active device.
+  virtual void SetOutputVolumeValue(double volume_percent) = 0;
+  // Sets the audio output mute value to prefs for the active device.
+  virtual void SetOutputMuteValue(bool mute_on) = 0;
+
+  // Reads the audio capture allowed value from prefs.
+  virtual bool GetAudioCaptureAllowedValue() = 0;
+  // Reads the audio output allowed value from prefs.
+  virtual bool GetAudioOutputAllowedValue() = 0;
+
+  // Adds an audio preference observer.
+  virtual void AddAudioPrefObserver(AudioPrefObserver* observer) = 0;
+  // Removes an audio preference observer.
+  virtual void RemoveAudioPrefObserver(AudioPrefObserver* observer) = 0;
+
+  // Creates the instance.
+  static AudioDevicesPrefHandler* Create(PrefService* local_state);
+
+ protected:
+  virtual ~AudioDevicesPrefHandler() {}
+
+ private:
+  friend class base::RefCountedThreadSafe<AudioDevicesPrefHandler>;
+};
+
+}  // namespace chromeos
+
+#endif  // CHROMEOS_AUDIO_AUDIO_DEVICES_PREF_HANDLER_H_
diff --git a/chromeos/audio/audio_pref_handler.h b/chromeos/audio/audio_pref_handler.h
index 08f38c0..89e4b7b 100644
--- a/chromeos/audio/audio_pref_handler.h
+++ b/chromeos/audio/audio_pref_handler.h
@@ -14,6 +14,8 @@ class PrefRegistrySimple;
 
 namespace chromeos {
 
+// TODO(jennyz,rkc): This class will be removed once we remove the old Audio
+// Handler code.
 // Interface that handles audio preference related work, reads and writes
 // audio preferences, and notifies AudioPrefObserver for audio preference
 // changes.
diff --git a/chromeos/audio/cras_audio_handler.cc b/chromeos/audio/cras_audio_handler.cc
index fc0a2eb..733fac9 100644
--- a/chromeos/audio/cras_audio_handler.cc
+++ b/chromeos/audio/cras_audio_handler.cc
@@ -10,7 +10,7 @@
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/logging.h"
-#include "chromeos/audio/audio_pref_handler.h"
+#include "chromeos/audio/audio_devices_pref_handler.h"
 #include "chromeos/audio/mock_cras_audio_handler.h"
 #include "chromeos/dbus/dbus_thread_manager.h"
 
@@ -58,7 +58,7 @@ void CrasAudioHandler::AudioObserver::OnActiveInputNodeChanged() {
 
 // static
 void CrasAudioHandler::Initialize(
-    scoped_refptr<AudioPrefHandler> audio_pref_handler) {
+    scoped_refptr<AudioDevicesPrefHandler> audio_pref_handler) {
   CHECK(!g_cras_audio_handler);
   g_cras_audio_handler = new CrasAudioHandler(audio_pref_handler);
 }
@@ -128,7 +128,6 @@ bool CrasAudioHandler::GetActiveOutputDevice(AudioDevice* device) const {
       return true;
     }
   }
-  NOTREACHED() << "Can't find active output audio device";
   return false;
 }
 
@@ -156,10 +155,8 @@ void CrasAudioHandler::AdjustOutputVolumeByPercent(int adjust_by_percent) {
 }
 
 void CrasAudioHandler::SetOutputMute(bool mute_on) {
-  if (output_mute_locked_) {
-    NOTREACHED() << "Output mute has been locked";
+  if (output_mute_locked_)
     return;
-  }
 
   chromeos::DBusThreadManager::Get()->GetCrasAudioClient()->
       SetOutputMute(mute_on);
@@ -174,10 +171,8 @@ void CrasAudioHandler::SetOutputMute(bool mute_on) {
 }
 
 void CrasAudioHandler::SetInputMute(bool mute_on) {
-  if (input_mute_locked_) {
-    NOTREACHED() << "Input mute has been locked";
+  if (input_mute_locked_)
     return;
-  }
 
   chromeos::DBusThreadManager::Get()->GetCrasAudioClient()->
       SetInputMute(mute_on);
@@ -194,7 +189,7 @@ void CrasAudioHandler::SetActiveInputNode(uint64 node_id) {
 }
 
 CrasAudioHandler::CrasAudioHandler(
-    scoped_refptr<AudioPrefHandler> audio_pref_handler)
+    scoped_refptr<AudioDevicesPrefHandler> audio_pref_handler)
     : audio_pref_handler_(audio_pref_handler),
       weak_ptr_factory_(this),
       output_mute_on_(false),
@@ -216,7 +211,7 @@ CrasAudioHandler::CrasAudioHandler(
     return;
   chromeos::DBusThreadManager::Get()->GetCrasAudioClient()->AddObserver(this);
   audio_pref_handler_->AddAudioPrefObserver(this);
-  SetupInitialAudioState();
+  GetNodes();
 }
 
 CrasAudioHandler::~CrasAudioHandler() {
@@ -232,7 +227,7 @@ CrasAudioHandler::~CrasAudioHandler() {
 }
 
 void CrasAudioHandler::AudioClientRestarted() {
-  SetupInitialAudioState();
+  GetNodes();
 }
 
 void CrasAudioHandler::OutputVolumeChanged(int volume) {
@@ -271,7 +266,7 @@ void CrasAudioHandler::ActiveOutputNodeChanged(uint64 node_id) {
     return;
 
   active_output_node_id_ = node_id;
-  GetNodes();
+  SetupAudioState();
   FOR_EACH_OBSERVER(AudioObserver, observers_, OnActiveOutputNodeChanged());
 }
 
@@ -280,7 +275,6 @@ void CrasAudioHandler::ActiveInputNodeChanged(uint64 node_id) {
     return;
 
   active_input_node_id_ = node_id;
-  GetNodes();
   FOR_EACH_OBSERVER(AudioObserver, observers_, OnActiveInputNodeChanged());
 }
 
@@ -288,7 +282,7 @@ void CrasAudioHandler::OnAudioPolicyPrefChanged() {
   ApplyAudioPolicy();
 }
 
-void CrasAudioHandler::SetupInitialAudioState() {
+void CrasAudioHandler::SetupAudioState() {
   ApplyAudioPolicy();
 
   // Set the initial audio state to the ones read from audio prefs.
@@ -296,9 +290,6 @@ void CrasAudioHandler::SetupInitialAudioState() {
   output_volume_ = audio_pref_handler_->GetOutputVolumeValue();
   SetOutputVolumeInternal(output_volume_);
   SetOutputMute(output_mute_on_);
-
-  // Get the initial audio data.
-  GetNodes();
 }
 
 void CrasAudioHandler::ApplyAudioPolicy() {
@@ -359,6 +350,7 @@ void CrasAudioHandler::HandleGetNodes(const chromeos::AudioNodeList& node_list,
     }
   }
 
+  SetupAudioState();
   FOR_EACH_OBSERVER(AudioObserver, observers_, OnAudioNodesChanged());
 }
 
diff --git a/chromeos/audio/cras_audio_handler.h b/chromeos/audio/cras_audio_handler.h
index 808d0e6..fd9ac03 100644
--- a/chromeos/audio/cras_audio_handler.h
+++ b/chromeos/audio/cras_audio_handler.h
@@ -20,7 +20,7 @@ class PrefService;
 
 namespace chromeos {
 
-class AudioPrefHandler;
+class AudioDevicesPrefHandler;
 
 class CHROMEOS_EXPORT CrasAudioHandler : public CrasAudioClient::Observer,
                                          public AudioPrefObserver {
@@ -52,7 +52,8 @@ class CHROMEOS_EXPORT CrasAudioHandler : public CrasAudioClient::Observer,
   };
 
   // Sets the global instance. Must be called before any calls to Get().
-  static void Initialize(scoped_refptr<AudioPrefHandler> audio_pref_handler);
+  static void Initialize(
+      scoped_refptr<AudioDevicesPrefHandler> audio_pref_handler);
 
   // Sets the global instance for testing.
   static void InitializeForTesting();
@@ -117,7 +118,8 @@ class CHROMEOS_EXPORT CrasAudioHandler : public CrasAudioClient::Observer,
   virtual void SetActiveInputNode(uint64 node_id);
 
  protected:
-  explicit CrasAudioHandler(scoped_refptr<AudioPrefHandler> audio_pref_handler);
+  explicit CrasAudioHandler(
+      scoped_refptr<AudioDevicesPrefHandler> audio_pref_handler);
   virtual ~CrasAudioHandler();
 
  private:
@@ -133,9 +135,9 @@ class CHROMEOS_EXPORT CrasAudioHandler : public CrasAudioClient::Observer,
   // Overriden from AudioPrefObserver.
   virtual void OnAudioPolicyPrefChanged() OVERRIDE;
 
-  // Sets up the initial audio device state based on audio policy and
-  // audio settings saved in prefs.
-  void SetupInitialAudioState();
+  // Sets up the audio device state based on audio policy and audio settings
+  // saved in prefs.
+  void SetupAudioState();
 
   // Applies the audio muting policies whenever the user logs in or policy
   // change notification is received.
@@ -150,7 +152,7 @@ class CHROMEOS_EXPORT CrasAudioHandler : public CrasAudioClient::Observer,
   // Handles dbus callback for GetNodes.
   void HandleGetNodes(const chromeos::AudioNodeList& node_list, bool success);
 
-  scoped_refptr<AudioPrefHandler> audio_pref_handler_;
+  scoped_refptr<AudioDevicesPrefHandler> audio_pref_handler_;
   base::WeakPtrFactory<CrasAudioHandler> weak_ptr_factory_;
   ObserverList<AudioObserver> observers_;
 
diff --git a/chromeos/audio/mock_cras_audio_handler.cc b/chromeos/audio/mock_cras_audio_handler.cc
index 84cd207..c6a47a9 100644
--- a/chromeos/audio/mock_cras_audio_handler.cc
+++ b/chromeos/audio/mock_cras_audio_handler.cc
@@ -4,7 +4,7 @@
 
 #include "chromeos/audio/mock_cras_audio_handler.h"
 
-#include "chromeos/audio/audio_pref_handler.h"
+#include "chromeos/audio/audio_devices_pref_handler.h"
 
 namespace chromeos {
 
diff --git a/chromeos/chromeos.gyp b/chromeos/chromeos.gyp
index 251bbfe..c1466d1 100644
--- a/chromeos/chromeos.gyp
+++ b/chromeos/chromeos.gyp
@@ -32,6 +32,7 @@
       'sources': [
         'audio/audio_device.cc',
         'audio/audio_device.h',
+        'audio/audio_devices_pref_handler.h',
         'audio/audio_pref_observer.h',
         'audio/audio_pref_handler.h',
         'audio/cras_audio_handler.cc',