Move CancelableTaskTracker to //base/task/CancelableTaskTracker.

chrome/browser/notifications/message_center_settings_controller.h

Index: chrome/browser/notifications/message_center_settings_controller.h
diff --git a/chrome/browser/notifications/message_center_settings_controller.h b/chrome/browser/notifications/message_center_settings_controller.h
index d24a0203f4e02f148822b80052b547b528148180..7f2bc196f08ab5e97b9f47cee445e482009f6fcf 100644
--- a/chrome/browser/notifications/message_center_settings_controller.h
+++ b/chrome/browser/notifications/message_center_settings_controller.h
@@ -25,10 +25,13 @@
 #include "chrome/browser/chromeos/login/user_manager.h"
 #endif
 
-class CancelableTaskTracker;
 class Profile;
 class ProfileInfoCache;
 
+namespace base {
+class CancelableTaskTracker;
+}
+
 namespace chrome {
 struct FaviconImageResult;
 }
@@ -106,7 +109,7 @@ class MessageCenterSettingsController
   ObserverList<message_center::NotifierSettingsObserver> observers_;
 
   // The task tracker for loading favicons.
-  scoped_ptr<CancelableTaskTracker> favicon_tracker_;
+  scoped_ptr<base::CancelableTaskTracker> favicon_tracker_;
 
   scoped_ptr<extensions::AppIconLoader> app_icon_loader_;