Fix windows unit_tests after r263150

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@263155 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/notifications/message_center_notifications_unittest_win.cc

@@ -27,7 +27,9 @@ namespace message_center {
 
 class MessageCenterNotificationManagerTest : public testing::Test {
  protected:
-  MessageCenterNotificationManagerTest() {}
+  MessageCenterNotificationManagerTest() {
+    MessageCenterNotificationManager::RegisterPrefs(local_state_.registry());
+  }
 
   virtual void SetUp() {
     // Clear the preference and initialize.