Remove content::NotificationObserver dependency from most Prefs code.

chrome/browser/translate/translate_manager.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/translate/translate_manager.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
 #include "base/json/json_reader.h"
@@ skipping 391 matching lines @@
       // We should know about this profile since we are listening for
       // notifications on it.
       DCHECK(count == 1u);
       PrefChangeRegistrar* pref_change_registrar =
           pref_change_registrars_[pref_service];
       count = pref_change_registrars_.erase(pref_service);
       DCHECK(count == 1u);
       delete pref_change_registrar;
       break;
     }
-    case chrome::NOTIFICATION_PREF_CHANGED: {
-      DCHECK(*content::Details<std::string>(details).ptr() ==
-             prefs::kAcceptLanguages);
-      PrefService* prefs = content::Source<PrefService>(source).ptr();
-      InitAcceptLanguages(prefs);
-      break;
-    }
     default:
       NOTREACHED();
   }
 }
 
+void TranslateManager::OnPreferenceChanged(PrefServiceBase* service,
+                                           const std::string& pref_name) {
+  DCHECK_EQ(prefs::kAcceptLanguages, pref_name);
+  InitAcceptLanguages(static_cast<PrefService*>(service));
+}
+
 void TranslateManager::OnURLFetchComplete(const net::URLFetcher* source) {
   if (translate_script_request_pending_.get() != source &&
       language_list_request_pending_.get() != source) {
     // Looks like crash on Mac is possibly caused with callback entering here
     // with unknown fetcher when network is refreshed.
     scoped_ptr<const net::URLFetcher> delete_ptr(source);
     return;
   }
 
   bool error =
@@ skipping 491 matching lines @@
 
   for (size_t i = 0; i < infobar_helper->GetInfoBarCount(); ++i) {
     TranslateInfoBarDelegate* delegate =
         infobar_helper->GetInfoBarDelegateAt(i)->
             AsTranslateInfoBarDelegate();
     if (delegate)
       return delegate;
   }
   return NULL;
 }