Remove content::NotificationObserver dependency from most Prefs code.

chrome/browser/chromeos/system/ash_system_tray_delegate.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/chromeos/system/ash_system_tray_delegate.h"
 
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
 #include "ash/system/audio/audio_observer.h"
 #include "ash/system/bluetooth/bluetooth_observer.h"
 #include "ash/system/brightness/brightness_observer.h"
 #include "ash/system/chromeos/network/network_observer.h"
 #include "ash/system/date/clock_observer.h"
 #include "ash/system/drive/drive_observer.h"
 #include "ash/system/ime/ime_observer.h"
 #include "ash/system/power/power_status_observer.h"
 #include "ash/system/tray/system_tray.h"
 #include "ash/system/tray/system_tray_delegate.h"
 #include "ash/system/tray_accessibility.h"
 #include "ash/system/tray_caps_lock.h"
 #include "ash/system/user/update_observer.h"
 #include "ash/system/user/user_observer.h"
 #include "ash/volume_control_delegate.h"
 #include "base/bind_helpers.h"
 #include "base/callback.h"
 #include "base/chromeos/chromeos_version.h"
 #include "base/logging.h"
 #include "base/memory/weak_ptr.h"
+#include "base/prefs/public/pref_observer.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/chromeos/accessibility/accessibility_util.h"
 #include "chrome/browser/chromeos/audio/audio_handler.h"
 #include "chrome/browser/chromeos/cros/cros_library.h"
 #include "chrome/browser/chromeos/cros/network_library.h"
 #include "chrome/browser/chromeos/drive/drive_system_service.h"
 #include "chrome/browser/chromeos/input_method/input_method_manager.h"
 #include "chrome/browser/chromeos/input_method/input_method_util.h"
 #include "chrome/browser/chromeos/input_method/xkeyboard.h"
@@ skipping 105 matching lines @@
 
 class SystemTrayDelegate : public ash::SystemTrayDelegate,
                            public AudioHandler::VolumeObserver,
                            public PowerManagerClient::Observer,
                            public SessionManagerClient::Observer,
                            public NetworkMenuIcon::Delegate,
                            public NetworkMenu::Delegate,
                            public NetworkLibrary::NetworkManagerObserver,
                            public NetworkLibrary::NetworkObserver,
                            public NetworkLibrary::CellularDataPlanObserver,
+                           public PrefObserver,
                            public google_apis::DriveServiceObserver,
                            public content::NotificationObserver,
                            public input_method::InputMethodManager::Observer,
                            public system::TimezoneSettings::Observer,
                            public device::BluetoothAdapter::Observer,
                            public SystemKeyEventListener::CapsLockObserver,
                            public ash::NetworkTrayDelegate {
  public:
   explicit SystemTrayDelegate(ash::SystemTray* tray)
       : tray_(tray),
@@ skipping 917 matching lines @@
           if (observer)
             observer->OnUserUpdate();
         }
         break;
       }
       case chrome::NOTIFICATION_LOGIN_USER_PROFILE_PREPARED: {
         // GData system service exists by the time if enabled.
         ObserveGDataUpdates();
         break;
       }
-      case chrome::NOTIFICATION_PREF_CHANGED: {
-        std::string pref = *content::Details<std::string>(details).ptr();
-        PrefService* service = content::Source<PrefService>(source).ptr();
-        if (pref == prefs::kUse24HourClock) {
-          UpdateClockType(service);
-        } else if (pref == prefs::kLanguageXkbRemapSearchKeyTo) {
-          search_key_mapped_to_ =
-              service->GetInteger(prefs::kLanguageXkbRemapSearchKeyTo);
-        } else if (pref == prefs::kSpokenFeedbackEnabled) {
-          ash::AccessibilityObserver* observer =
-              tray_->accessibility_observer();
-          if (observer) {
-            observer->OnAccessibilityModeChanged(
-                service->GetBoolean(prefs::kSpokenFeedbackEnabled));
-          }
-        } else {
-          NOTREACHED();
-        }
-        break;
-      }
       case chrome::NOTIFICATION_PROFILE_CREATED: {
         SetProfile(content::Source<Profile>(source).ptr());
         registrar_.Remove(this,
                           chrome::NOTIFICATION_PROFILE_CREATED,
                           content::NotificationService::AllSources());
         break;
       }
       case chrome::NOTIFICATION_SESSION_STARTED: {
         ash::Shell::GetInstance()->UpdateAfterLoginStatusChange(
             GetUserLoginStatus());
         SetProfile(ProfileManager::GetDefaultProfile());
         break;
       }
       default:
         NOTREACHED();
     }
   }
 
+  virtual void OnPreferenceChanged(PrefServiceBase* service,
+                                   const std::string& pref) OVERRIDE {
+    if (pref == prefs::kUse24HourClock) {
+      UpdateClockType(static_cast<PrefService*>(service));
+    } else if (pref == prefs::kLanguageXkbRemapSearchKeyTo) {
+      search_key_mapped_to_ =
+          service->GetInteger(prefs::kLanguageXkbRemapSearchKeyTo);
+    } else if (pref == prefs::kSpokenFeedbackEnabled) {
+      ash::AccessibilityObserver* observer =
+          tray_->accessibility_observer();
+      if (observer) {
+        observer->OnAccessibilityModeChanged(
+            service->GetBoolean(prefs::kSpokenFeedbackEnabled));
+      }
+    } else {
+      NOTREACHED();
+    }
+  }
+
   // Overridden from InputMethodManager::Observer.
   virtual void InputMethodChanged(
       input_method::InputMethodManager* manager, bool show_message) OVERRIDE {
     NotifyRefreshIME(show_message);
   }
 
   virtual void InputMethodPropertyChanged(
       input_method::InputMethodManager* manager) OVERRIDE {
     NotifyRefreshIME(false);
   }
@@ skipping 161 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(SystemTrayDelegate);
 };
 
 }  // namespace
 
 ash::SystemTrayDelegate* CreateSystemTrayDelegate(ash::SystemTray* tray) {
   return new chromeos::SystemTrayDelegate(tray);
 }
 
 }  // namespace chromeos