Add a new audio extension event OnLevelChanged.

chromeos/audio/cras_audio_handler.cc

 // 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 "chromeos/audio/cras_audio_handler.h"
 
 #include <algorithm>
 #include <cmath>
 
 #include "base/bind.h"
@@ skipping 37 matching lines @@
 }
 
 }  // namespace
 
 CrasAudioHandler::AudioObserver::AudioObserver() {
 }
 
 CrasAudioHandler::AudioObserver::~AudioObserver() {
 }
 
-void CrasAudioHandler::AudioObserver::OnOutputVolumeChanged() {
+void CrasAudioHandler::AudioObserver::OnOutputNodeVolumeChanged(uint64 node_id,
+                                                                double volume) {
 }
 
 void CrasAudioHandler::AudioObserver::OnInputGainChanged() {
 }
 
 void CrasAudioHandler::AudioObserver::OnOutputMuteChanged() {
 }
 
 void CrasAudioHandler::AudioObserver::OnInputMuteChanged() {
 }
@@ skipping 560 matching lines @@
   volume_percent = min(max(volume_percent, 0), 100);
   if (volume_percent <= kMuteThresholdPercent)
     volume_percent = 0;
   if (node_id == active_output_node_id_)
     output_volume_ = volume_percent;
 
   audio_pref_handler_->SetVolumeGainValue(*device, volume_percent);
 
   if (device->active) {
     SetOutputNodeVolume(node_id, volume_percent);
-    FOR_EACH_OBSERVER(AudioObserver, observers_, OnOutputVolumeChanged());
+    FOR_EACH_OBSERVER(AudioObserver, observers_,
+                      OnOutputNodeVolumeChanged(node_id, volume_percent));
   }
 }
 
 bool  CrasAudioHandler::SetOutputMuteInternal(bool mute_on) {
   if (output_mute_locked_)
     return false;
 
   output_mute_on_ = mute_on;
   chromeos::DBusThreadManager::Get()->GetCrasAudioClient()->
       SetOutputUserMute(mute_on);
@@ skipping 309 matching lines @@
       active_output_node_id_ = 0;
     chromeos::DBusThreadManager::Get()
         ->GetCrasAudioClient()
         ->RemoveActiveOutputNode(node_id);
     if (notify)
       NotifyActiveNodeChanged(false);
   }
 }
 
 }  // namespace chromeos