Remove content::NotificationObserver dependency from most Prefs code.

chrome/browser/speech/chrome_speech_recognition_preferences.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/speech/chrome_speech_recognition_preferences.h"
 
 #include "base/bind.h"
 #include "base/values.h"
 #include "chrome/browser/prefs/pref_service.h"
 #include "chrome/browser/profiles/profile.h"
@@ skipping 123 matching lines @@
 ChromeSpeechRecognitionPreferences::~ChromeSpeechRecognitionPreferences() {
 }
 
 void ChromeSpeechRecognitionPreferences::DetachFromProfile() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   DCHECK(profile_);
   pref_change_registrar_.reset();
   profile_ = NULL;
 }
 
-void ChromeSpeechRecognitionPreferences::Observe(
-    int type,
-    const content::NotificationSource& source,
-    const content::NotificationDetails& details) {
+void ChromeSpeechRecognitionPreferences::OnPreferenceChanged(
+    PrefServiceBase* service,
+    const std::string& pref_name) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  DCHECK_EQ(type, chrome::NOTIFICATION_PREF_CHANGED);
-  std::string* pref_name = content::Details<std::string>(details).ptr();
-  ReloadPreference(*pref_name);
+  ReloadPreference(pref_name);
 }
 
 bool ChromeSpeechRecognitionPreferences::FilterProfanities() const {
   base::AutoLock read_lock(preferences_lock_);
   return filter_profanities_;
 }
 
 void ChromeSpeechRecognitionPreferences::SetFilterProfanities(
     bool filter_profanities) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
@@ skipping 43 matching lines @@
   if (key == prefs::kSpeechRecognitionFilterProfanities) {
     filter_profanities_ =
           pref_service->GetBoolean(prefs::kSpeechRecognitionFilterProfanities);
   } else if (key == prefs::kSpeechRecognitionTrayNotificationShownContexts) {
     const base::ListValue* pref_list = profile_->GetPrefs()->GetList(
         prefs::kSpeechRecognitionTrayNotificationShownContexts);
     DCHECK(pref_list);
     notifications_shown_.reset(pref_list->DeepCopy());
   }
 }