Rewrite scoped_ptr<T>(NULL) to use the default ctor in chrome/.

chrome/browser/notifications/balloon_notification_ui_manager.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/notifications/balloon_notification_ui_manager.h"
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/prefs/pref_service.h"
 #include "base/stl_util.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/fullscreen.h"
 #include "chrome/browser/idle.h"
 #include "chrome/browser/notifications/balloon_collection.h"
 #include "chrome/browser/notifications/notification.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/common/chrome_notification_types.h"
 #include "chrome/common/pref_names.h"
 #include "content/public/browser/notification_service.h"
 
 BalloonNotificationUIManager::BalloonNotificationUIManager(
     PrefService* local_state)
-    : NotificationUIManagerImpl(),
-      NotificationPrefsManager(local_state),
-      balloon_collection_(NULL) {
+    : NotificationUIManagerImpl(), NotificationPrefsManager(local_state) {
   position_pref_.Init(
       prefs::kDesktopNotificationPosition,
       local_state,
       base::Bind(
           &BalloonNotificationUIManager::OnDesktopNotificationPositionChanged,
           base::Unretained(this)));
 }
 
 BalloonNotificationUIManager::~BalloonNotificationUIManager() {
 }
@@ skipping 132 matching lines @@
     BalloonNotificationUIManager::GetInstanceForTesting() {
   if (NotificationUIManager::DelegatesToMessageCenter()) {
     LOG(ERROR) << "Attempt to run a test that requires "
                << "BalloonNotificationUIManager while delegating to a "
                << "native MessageCenter. Test will fail. Ask dimich@";
     return NULL;
   }
   return static_cast<BalloonNotificationUIManager*>(
       g_browser_process->notification_ui_manager());
 }