Refactor the TrayAudio code so that it can be used by other platforms.

chrome/browser/ui/ash/system_tray_delegate_chromeos.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 "chrome/browser/ui/ash/system_tray_delegate_chromeos.h"
 
 #include <algorithm>
 #include <set>
 #include <string>
 #include <vector>
@@ skipping 293 matching lines @@
 
   device::BluetoothAdapterFactory::GetAdapter(
       base::Bind(&SystemTrayDelegateChromeOS::InitializeOnAdapterReady,
                  weak_ptr_factory_.GetWeakPtr()));
 
   ash::Shell::GetInstance()->session_state_delegate()->AddSessionStateObserver(
       this);
 
   if (LoginState::IsInitialized())
     LoginState::Get()->AddObserver(this);
+
+  if (CrasAudioHandler::IsInitialized())
+    CrasAudioHandler::Get()->AddAudioObserver(this);
 }
 
 void SystemTrayDelegateChromeOS::Shutdown() {
   device_settings_observer_.reset();
 }
 
 void SystemTrayDelegateChromeOS::InitializeOnAdapterReady(
     scoped_refptr<device::BluetoothAdapter> adapter) {
   bluetooth_adapter_ = adapter;
   CHECK(bluetooth_adapter_.get());
@@ skipping 34 matching lines @@
   DBusThreadManager::Get()->GetSessionManagerClient()->RemoveObserver(this);
   input_method::InputMethodManager::Get()->RemoveObserver(this);
   if (SystemKeyEventListener::GetInstance())
     SystemKeyEventListener::GetInstance()->RemoveCapsLockObserver(this);
   bluetooth_adapter_->RemoveObserver(this);
   ash::Shell::GetInstance()
       ->session_state_delegate()
       ->RemoveSessionStateObserver(this);
   LoginState::Get()->RemoveObserver(this);
 
-  // Stop observing Drive operations.
+  if (CrasAudioHandler::IsInitialized())
+    CrasAudioHandler::Get()->RemoveAudioObserver(this);
+
+// Stop observing Drive operations.
   UnobserveDriveUpdates();
 
   policy::BrowserPolicyConnectorChromeOS* connector =
       g_browser_process->platform_part()->browser_policy_connector_chromeos();
   policy::DeviceCloudPolicyManagerChromeOS* policy_manager =
       connector->GetDeviceCloudPolicyManager();
   if (policy_manager)
     policy_manager->core()->store()->RemoveObserver(this);
 }
 
@@ skipping 820 matching lines @@
     show_message = false;
   }
   GetSystemTrayNotifier()->NotifyRefreshIME(show_message);
 }
 
 void SystemTrayDelegateChromeOS::InputMethodPropertyChanged(
     input_method::InputMethodManager* manager) {
   GetSystemTrayNotifier()->NotifyRefreshIME(false);
 }
 
+// Overridden from CrasAudioHandler::AudioObserver.
+void SystemTrayDelegateChromeOS::OnOutputVolumeChanged() {
+  GetSystemTrayNotifier()->NotifyAudioOutputVolumeChanged();
+}
+
+void SystemTrayDelegateChromeOS::OnOutputMuteChanged() {
+  GetSystemTrayNotifier()->NotifyAudioOutputMuteChanged();
+}
+
+void SystemTrayDelegateChromeOS::OnInputGainChanged() {
+}
+
+void SystemTrayDelegateChromeOS::OnInputMuteChanged() {
+}
+
+void SystemTrayDelegateChromeOS::OnAudioNodesChanged() {
+  GetSystemTrayNotifier()->NotifyAudioNodesChanged();
+}
+
+void SystemTrayDelegateChromeOS::OnActiveOutputNodeChanged() {
+  GetSystemTrayNotifier()->NotifyAudioActiveOutputNodeChanged();
+}
+
+void SystemTrayDelegateChromeOS::OnActiveInputNodeChanged() {
+  GetSystemTrayNotifier()->NotifyAudioActiveInputNodeChanged();
+}
+
 // drive::JobListObserver overrides.
 void SystemTrayDelegateChromeOS::OnJobAdded(const drive::JobInfo& job_info) {
   OnJobUpdated(job_info);
 }
 
 void SystemTrayDelegateChromeOS::OnJobDone(const drive::JobInfo& job_info,
                                            drive::FileError error) {
   ash::DriveOperationStatus status;
   if (ConvertToFinishedDriveOperationStatus(job_info, error, &status))
     GetSystemTrayNotifier()->NotifyDriveJobUpdated(status);
@@ skipping 82 matching lines @@
 void SystemTrayDelegateChromeOS::UserAddedToSession(
     const std::string& user_id) {
   GetSystemTrayNotifier()->NotifyUserAddedToSession();
 }
 
 ash::SystemTrayDelegate* CreateSystemTrayDelegate() {
   return new SystemTrayDelegateChromeOS();
 }
 
 }  // namespace chromeos