Remove content::NotificationObserver dependency from most Prefs code.

chrome/browser/net/http_server_properties_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/net/http_server_properties_manager.h"
 
 #include "base/bind.h"
 #include "base/stl_util.h"
 #include "base/string_number_conversions.h"
 #include "base/stringprintf.h"
 #include "base/values.h"
@@ skipping 618 matching lines @@
   }
 
   http_server_properties_dict.SetWithoutPathExpansion("servers", servers_dict);
   http_server_properties_dict.SetInteger("version", kVersionNumber);
   setting_prefs_ = true;
   pref_service_->Set(prefs::kHttpServerProperties,
                      http_server_properties_dict);
   setting_prefs_ = false;
 }
 
-void HttpServerPropertiesManager::Observe(
-    int type,
-    const content::NotificationSource& source,
-    const content::NotificationDetails& details) {
+void HttpServerPropertiesManager::OnPreferenceChanged(
+    PrefServiceBase* prefs,
+    const std::string& pref_name) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
-  DCHECK(type == chrome::NOTIFICATION_PREF_CHANGED);
-  PrefService* prefs = content::Source<PrefService>(source).ptr();
   DCHECK(prefs == pref_service_);
-  std::string* pref_name = content::Details<std::string>(details).ptr();
-  if (*pref_name == prefs::kHttpServerProperties) {
+  if (pref_name == prefs::kHttpServerProperties) {
     if (!setting_prefs_)
       ScheduleUpdateCacheOnUI();
   } else {
     NOTREACHED();
   }
 }
 
 }  // namespace chrome_browser_net