Remove content::NotificationObserver dependency from most Prefs code.

chrome/browser/ui/gesture_prefs_observer_factory_aura.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/ui/gesture_prefs_observer_factory_aura.h"
 
 #include "base/compiler_specific.h"
 #include "base/prefs/public/pref_change_registrar.h"
+#include "base/prefs/public/pref_observer.h"
 #include "chrome/browser/prefs/pref_service.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile_dependency_manager.h"
 #include "chrome/common/chrome_notification_types.h"
 #include "chrome/common/pref_names.h"
 #include "content/public/browser/notification_observer.h"
 #include "ui/base/gestures/gesture_configuration.h"
 
 using ui::GestureConfiguration;
 
 namespace {
 
 // This class manages gesture configuration preferences.
-class GesturePrefsObserver : public content::NotificationObserver,
+class GesturePrefsObserver : public PrefObserver,
                              public ProfileKeyedService {
  public:
   explicit GesturePrefsObserver(PrefService* prefs);
   virtual ~GesturePrefsObserver();
 
   // ProfileKeyedService implementation.
   virtual void Shutdown() OVERRIDE;
 
-  // content::NotificationObserver implementation.
-  virtual void Observe(int type,
-                       const content::NotificationSource& source,
-                       const content::NotificationDetails& details) OVERRIDE;
+  // PrefObserver implementation.
+  virtual void OnPreferenceChanged(PrefServiceBase* service,
+                                   const std::string& pref_name) OVERRIDE;
 
  private:
   void Update();
 
   PrefChangeRegistrar registrar_;
   PrefService* prefs_;
 
   DISALLOW_COPY_AND_ASSIGN(GesturePrefsObserver);
 };
 
@@ skipping 29 matching lines @@
   for (size_t i = 0; i < arraysize(kPrefsToObserve); ++i)
     registrar_.Add(kPrefsToObserve[i], this);
 }
 
 GesturePrefsObserver::~GesturePrefsObserver() {}
 
 void GesturePrefsObserver::Shutdown() {
   registrar_.RemoveAll();
 }
 
-void GesturePrefsObserver::Observe(
-    int type,
-    const content::NotificationSource& source,
-    const content::NotificationDetails& details) {
+void GesturePrefsObserver::OnPreferenceChanged(PrefServiceBase* service,
+                                               const std::string& pref_name) {
   Update();
 }
 
 void GesturePrefsObserver::Update() {
   GestureConfiguration::set_long_press_time_in_seconds(
       prefs_->GetDouble(
           prefs::kLongPressTimeInSeconds));
   GestureConfiguration::set_semi_long_press_time_in_seconds(
       prefs_->GetDouble(
           prefs::kSemiLongPressTimeInSeconds));
@@ skipping 164 matching lines @@
   // Use same gesture preferences on incognito windows.
   return true;
 }
 
 bool GesturePrefsObserverFactoryAura::ServiceIsNULLWhileTesting() const {
   // Some tests replace the PrefService of the TestingProfile after the
   // GesturePrefsObserver has been created, which makes Shutdown()
   // remove the registrar from a non-existent PrefService.
   return true;
 }