Remove content::NotificationObserver dependency from most Prefs code.

chrome/browser/chromeos/audio/audio_handler.cc

 // Copyright (c) 2012 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_handler.h"
 
 #include <algorithm>
 #include <cmath>
 
 #include "base/logging.h"
 #include "base/memory/singleton.h"
 #include "chrome/browser/browser_process.h"
 #if defined(USE_CRAS)
 #include "chrome/browser/chromeos/audio/audio_mixer_cras.h"
 #else
 #include "chrome/browser/chromeos/audio/audio_mixer_alsa.h"
 #endif
 #include "chrome/browser/prefs/pref_service.h"
 #include "chrome/common/chrome_notification_types.h"
 #include "chrome/common/pref_names.h"
 #include "content/public/browser/browser_thread.h"
-#include "content/public/browser/notification_service.h"
 
 using std::max;
 using std::min;
 
 namespace chromeos {
 
 namespace {
 
 // Default value for the volume pref, as a percent in the range [0.0, 100.0].
 const double kDefaultVolumePercent = 75.0;
@@ skipping 121 matching lines @@
 }
 
 void AudioHandler::AddVolumeObserver(VolumeObserver* observer) {
   volume_observers_.AddObserver(observer);
 }
 
 void AudioHandler::RemoveVolumeObserver(VolumeObserver* observer) {
   volume_observers_.RemoveObserver(observer);
 }
 
-void AudioHandler::Observe(int type,
-                           const content::NotificationSource& source,
-                           const content::NotificationDetails& details) {
-  if (type == chrome::NOTIFICATION_PREF_CHANGED) {
-    std::string* pref_name = content::Details<std::string>(details).ptr();
-    if (*pref_name == prefs::kAudioOutputAllowed ||
-        *pref_name == prefs::kAudioCaptureAllowed) {
-      ApplyAudioPolicy();
-    }
-  } else {
-    NOTREACHED() << "Unexpected notification type : " << type;
-  }
+void AudioHandler::OnPreferenceChanged(PrefServiceBase* service,
+                                       const std::string& pref_name) {
+  DCHECK(pref_name == prefs::kAudioOutputAllowed ||
+         pref_name == prefs::kAudioCaptureAllowed);
+  ApplyAudioPolicy();
 }
 
 AudioHandler::AudioHandler(AudioMixer* mixer)
     : mixer_(mixer),
       local_state_(g_browser_process->local_state()) {
   InitializePrefObservers();
   mixer_->Init();
   ApplyAudioPolicy();
   SetMuted(local_state_->GetInteger(prefs::kAudioMute) == kPrefMuteOn);
   SetVolumePercentInternal(local_state_->GetDouble(prefs::kAudioVolumePercent));
@@ skipping 22 matching lines @@
   mixer_->SetCaptureMuteLocked(false);
   if (local_state_->GetBoolean(prefs::kAudioCaptureAllowed)) {
     mixer_->SetCaptureMuted(false);
   } else {
     mixer_->SetCaptureMuted(true);
     mixer_->SetCaptureMuteLocked(true);
   }
 }
 
 }  // namespace chromeos