Remove content::NotificationObserver dependency from most Prefs code.

chrome/browser/net/net_pref_observer.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/net_pref_observer.h"
 
 #include "chrome/browser/net/predictor.h"
 #include "chrome/browser/prefs/pref_service.h"
 #include "chrome/browser/prerender/prerender_manager.h"
 #include "chrome/common/chrome_notification_types.h"
@@ skipping 16 matching lines @@
                                    this);
   spdy_disabled_.Init(prefs::kDisableSpdy, prefs, this);
 
   ApplySettings();
 }
 
 NetPrefObserver::~NetPrefObserver() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 }
 
-void NetPrefObserver::Observe(int type,
-                              const content::NotificationSource& source,
-                              const content::NotificationDetails& details) {
-  DCHECK_EQ(type, chrome::NOTIFICATION_PREF_CHANGED);
+void NetPrefObserver::OnPreferenceChanged(PrefServiceBase* service,
+                                          const std::string& pref_name) {
   ApplySettings();
 }
 
 void NetPrefObserver::ApplySettings() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   predictor_->EnablePredictor(*network_prediction_enabled_);
   if (prerender_manager_)
     prerender_manager_->set_enabled(*network_prediction_enabled_);
   if (spdy_disabled_.IsManaged())
     net::HttpStreamFactory::set_spdy_enabled(!*spdy_disabled_);
 }
 
 // static
 void NetPrefObserver::RegisterPrefs(PrefService* prefs) {
   prefs->RegisterBooleanPref(prefs::kNetworkPredictionEnabled,
                              true,
                              PrefService::SYNCABLE_PREF);
   prefs->RegisterBooleanPref(prefs::kDisableSpdy,
                              false,
                              PrefService::UNSYNCABLE_PREF);
 }