Remove content::NotificationObserver dependency from most Prefs code.

chrome/browser/protector/protected_prefs_watcher.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/protector/protected_prefs_watcher.h"
 
 #include "base/base64.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/stringprintf.h"
@@ skipping 177 matching lines @@
 }
 
 void ProtectedPrefsWatcher::ForceUpdateBackup() {
   UMA_HISTOGRAM_ENUMERATION(
       kProtectorHistogramPrefs,
       kProtectorErrorForcedUpdate,
       kProtectorErrorCount);
   InitBackup();
 }
 
-void ProtectedPrefsWatcher::Observe(
-    int type,
-    const content::NotificationSource& source,
-    const content::NotificationDetails& details) {
-  DCHECK(type == chrome::NOTIFICATION_PREF_CHANGED);
-  const std::string* pref_name = content::Details<std::string>(details).ptr();
-  DCHECK(pref_name && pref_observer_.IsObserved(*pref_name));
-  if (UpdateBackupEntry(*pref_name))
+void ProtectedPrefsWatcher::OnPreferenceChanged(PrefServiceBase* service,
+                                                const std::string& pref_name) {
+  DCHECK(pref_observer_.IsObserved(pref_name));
+  if (UpdateBackupEntry(pref_name))
     UpdateBackupSignature();
 }
 
 void ProtectedPrefsWatcher::EnsurePrefsMigration() {
   SessionStartupPref::MigrateIfNecessary(profile_->GetPrefs());
 }
 
 bool ProtectedPrefsWatcher::UpdateCachedPrefs() {
   // ExtensionService may not yet have been initialized, so using static method
   // exposed for this purpose.
@@ skipping 176 matching lines @@
         NOTREACHED();
         continue;
       }
       StringAppendStringDictionary(tab, &data);
     }
   }
   return data;
 }
 
 }  // namespace protector