chromeos: Make system tray audio item observe CrasAudioHandler directly

chrome/browser/ui/ash/system_tray_delegate_chromeos.cc

Index: chrome/browser/ui/ash/system_tray_delegate_chromeos.cc
diff --git a/chrome/browser/ui/ash/system_tray_delegate_chromeos.cc b/chrome/browser/ui/ash/system_tray_delegate_chromeos.cc
index 885b86a504296f991e380fa4c2a1980cf19d4513..534ed5de9dc4eec06e642cf8a43215bebce18aa9 100644
--- a/chrome/browser/ui/ash/system_tray_delegate_chromeos.cc
+++ b/chrome/browser/ui/ash/system_tray_delegate_chromeos.cc
@@ -192,9 +192,6 @@ void SystemTrayDelegateChromeOS::Initialize() {
 
   ash::WmShell::Get()->GetSessionStateDelegate()->AddSessionStateObserver(this);
 
-  if (CrasAudioHandler::IsInitialized())
-    CrasAudioHandler::Get()->AddAudioObserver(this);
-
   BrowserList::AddObserver(this);
 }
 
@@ -247,9 +244,6 @@ SystemTrayDelegateChromeOS::~SystemTrayDelegateChromeOS() {
   ash::WmShell::Get()->GetSessionStateDelegate()->RemoveSessionStateObserver(
       this);
 
-  if (CrasAudioHandler::IsInitialized())
-    CrasAudioHandler::Get()->RemoveAudioObserver(this);
-
   BrowserList::RemoveObserver(this);
   StopObservingAppWindowRegistry();
   StopObservingCustodianInfoChanges();
@@ -880,36 +874,6 @@ void SystemTrayDelegateChromeOS::InputMethodMenuItemChanged(
   GetSystemTrayNotifier()->NotifyRefreshIME();
 }
 
-// Overridden from CrasAudioHandler::AudioObserver.
-void SystemTrayDelegateChromeOS::OnOutputNodeVolumeChanged(uint64_t node_id,
-                                                           int volume) {
-  GetSystemTrayNotifier()->NotifyAudioOutputVolumeChanged(node_id, volume);
-}
-
-void SystemTrayDelegateChromeOS::OnOutputMuteChanged(bool mute_on,
-                                                     bool system_adjust) {
-  GetSystemTrayNotifier()->NotifyAudioOutputMuteChanged(mute_on, system_adjust);
-}
-
-void SystemTrayDelegateChromeOS::OnInputNodeGainChanged(uint64_t /* node_id */,
-                                                        int /* gain */) {
-}
-
-void SystemTrayDelegateChromeOS::OnInputMuteChanged(bool /* mute_on */) {
-}
-
-void SystemTrayDelegateChromeOS::OnAudioNodesChanged() {
-  GetSystemTrayNotifier()->NotifyAudioNodesChanged();
-}
-
-void SystemTrayDelegateChromeOS::OnActiveOutputNodeChanged() {
-  GetSystemTrayNotifier()->NotifyAudioActiveOutputNodeChanged();
-}
-
-void SystemTrayDelegateChromeOS::OnActiveInputNodeChanged() {
-  GetSystemTrayNotifier()->NotifyAudioActiveInputNodeChanged();
-}
-
 // Overridden from BluetoothAdapter::Observer.
 void SystemTrayDelegateChromeOS::AdapterPresentChanged(
     device::BluetoothAdapter* adapter,