Add the layout test case of ash/popup_message.

ash/popup_message.h

 // Copyright 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.
 
 #ifndef ASH_POPUP_MESSAGE_H_
 #define ASH_POPUP_MESSAGE_H_
 
 #include "ash/ash_export.h"
 #include "base/basictypes.h"
+#include "base/gtest_prod_util.h"
 #include "base/strings/string16.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/views/bubble/bubble_border.h"
 
 namespace views {
 class BubbleDelegateView;
 class Widget;
 }
 
 namespace ash {
@@ skipping 35 matching lines @@
                const gfx::Size& size_override,
                int arrow_offset);
   // If the message was not explicitly closed before, it closes the message
   // without animation.
   virtual ~PopupMessage();
 
   // Closes the message with a fade out animation.
   void Close();
 
  private:
+  FRIEND_TEST_ALL_PREFIXES(PopupMessageTest, Layout);
+
   class MessageBubble;
 
+  static const int kCaptionLabelID;
+  static const int kMessageLabelID;
+
   void CancelHidingAnimation();
 
   MessageBubble* view_;
   views::Widget* widget_;
 
   base::string16 caption_;
   base::string16 message_;
 
   DISALLOW_COPY_AND_ASSIGN(PopupMessage);
 };
 
 }  // namespace ash
 
 #endif  // ASH_POPUP_MESSAGE_H_