Use a direct include of strings headers in ui/, part 2.

ui/message_center/cocoa/notification_controller.mm

 // Copyright (c) 2013 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.
 
 #import "ui/message_center/cocoa/notification_controller.h"
 
 #include "base/mac/foundation_util.h"
-#include "base/string_util.h"
+#include "base/strings/string_util.h"
+#include "base/strings/sys_string_conversions.h"
 #include "base/strings/utf_string_conversions.h"
-#include "base/strings/sys_string_conversions.h"
 #include "grit/ui_resources.h"
 #include "skia/ext/skia_utils_mac.h"
 #import "ui/base/cocoa/hover_image_button.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/base/text/text_elider.h"
 #include "ui/message_center/message_center.h"
 #include "ui/message_center/message_center_style.h"
 #include "ui/message_center/notification.h"
 
 @interface MCNotificationButtonCell : NSButtonCell {
@@ skipping 512 matching lines @@
     if (font.GetStringWidth(last) > width)
       last = ui::ElideText(last, font, width, ui::ELIDE_AT_END);
     wrapped.resize(lines - 1);
     wrapped.push_back(last);
   }
 
   return JoinString(wrapped, '\n');
 }
 
 @end