Remove content::NotificationObserver dependency from most Prefs code.

chrome/browser/ui/ash/launcher/chrome_launcher_controller.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/ash/launcher/chrome_launcher_controller.h"
 
 #include <set>
 #include <vector>
 
 #include "ash/launcher/launcher_model.h"
@@ skipping 766 matching lines @@
     }
     case chrome::NOTIFICATION_EXTENSION_UNLOADED: {
       const content::Details<extensions::UnloadedExtensionInfo> unload_info(
           details);
       const Extension* extension = unload_info->extension;
       if (IsAppPinned(extension->id()))
         DoUnpinAppsWithID(extension->id());
       app_icon_loader_->ClearImage(extension->id());
       break;
     }
-    case chrome::NOTIFICATION_PREF_CHANGED: {
-      const std::string& pref_name(
-          *content::Details<std::string>(details).ptr());
-      if (pref_name == prefs::kPinnedLauncherApps) {
-        UpdateAppLaunchersFromPref();
-      } else if (pref_name == prefs::kShelfAlignmentLocal) {
-        SetShelfAlignmentFromPrefs();
-      } else if (pref_name == prefs::kShelfAutoHideBehaviorLocal) {
-        SetShelfAutoHideBehaviorFromPrefs();
-      } else {
-        NOTREACHED() << "Unexpected pref change for " << pref_name;
-      }
-      break;
-    }
     default:
       NOTREACHED() << "Unexpected notification type=" << type;
   }
 }
 
+void ChromeLauncherController::OnPreferenceChanged(
+    PrefServiceBase* service,
+    const std::string& pref_name) {
+  if (pref_name == prefs::kPinnedLauncherApps) {
+    UpdateAppLaunchersFromPref();
+  } else if (pref_name == prefs::kShelfAlignmentLocal) {
+    SetShelfAlignmentFromPrefs();
+  } else if (pref_name == prefs::kShelfAutoHideBehaviorLocal) {
+    SetShelfAutoHideBehaviorFromPrefs();
+  } else {
+    NOTREACHED() << "Unexpected pref change for " << pref_name;
+  }
+}
+
 void ChromeLauncherController::OnShelfAlignmentChanged() {
   const char* pref_value = NULL;
   // TODO(oshima): Support multiple displays.
   switch (ash::Shell::GetInstance()->GetShelfAlignment(
       ash::Shell::GetPrimaryRootWindow())) {
     case ash::SHELF_ALIGNMENT_BOTTOM:
       pref_value = ash::kShelfAlignmentBottom;
       break;
     case ash::SHELF_ALIGNMENT_LEFT:
       pref_value = ash::kShelfAlignmentLeft;
@@ skipping 304 matching lines @@
 }
 
 void ChromeLauncherController::StopLoadingAnimation() {
   DCHECK(observed_sync_service_);
 
   model_->SetStatus(ash::LauncherModel::STATUS_NORMAL);
   loading_timer_.Stop();
   observed_sync_service_->RemoveObserver(this);
   observed_sync_service_ = NULL;
 }