Remove content::NotificationObserver dependency from most Prefs code.

chrome/browser/sync/sync_prefs.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/sync/sync_prefs.h"
 
 #include "base/logging.h"
 #include "base/string_number_conversions.h"
 #include "base/values.h"
 #include "build/build_config.h"
@@ skipping 245 matching lines @@
   const syncer::ModelTypeSet acknowledged_types =
       Union(types,
             syncer::ModelTypeSetFromValue(
                 *pref_service_->GetList(prefs::kSyncAcknowledgedSyncTypes)));
 
   scoped_ptr<ListValue> value(
       syncer::ModelTypeSetToValue(acknowledged_types));
   pref_service_->Set(prefs::kSyncAcknowledgedSyncTypes, *value);
 }
 
-void SyncPrefs::Observe(int type,
-                        const content::NotificationSource& source,
-                        const content::NotificationDetails& details) {
+void SyncPrefs::OnPreferenceChanged(PrefServiceBase* service,
+                                    const std::string& pref_name) {
   DCHECK(CalledOnValidThread());
-  DCHECK(content::Source<PrefService>(pref_service_) == source);
-  switch (type) {
-    case chrome::NOTIFICATION_PREF_CHANGED: {
-      const std::string* pref_name =
-          content::Details<const std::string>(details).ptr();
-      if (*pref_name == prefs::kSyncManaged) {
-        FOR_EACH_OBSERVER(SyncPrefObserver, sync_pref_observers_,
-                          OnSyncManagedPrefChange(*pref_sync_managed_));
-      }
-      break;
-    }
-    default:
-      NOTREACHED();
-      break;
+  DCHECK_EQ(pref_service_, service);
+  if (pref_name == prefs::kSyncManaged) {
+    FOR_EACH_OBSERVER(SyncPrefObserver, sync_pref_observers_,
+                      OnSyncManagedPrefChange(*pref_sync_managed_));
   }
 }
 
 void SyncPrefs::SetManagedForTest(bool is_managed) {
   DCHECK(CalledOnValidThread());
   CHECK(pref_service_);
   pref_service_->SetBoolean(prefs::kSyncManaged, is_managed);
 }
 
 syncer::ModelTypeSet SyncPrefs::GetAcknowledgeSyncedTypesForTest() const {
@@ skipping 145 matching lines @@
     if (types.Has(i->first))
       types_with_groups.PutAll(i->second);
     else
       types_with_groups.RemoveAll(i->second);
   }
   types_with_groups.RetainAll(registered_types);
   return types_with_groups;
 }
 
 }  // namespace browser_sync