athena: Move athena_export.h into common/ directory.

athena/virtual_keyboard/public/virtual_keyboard_manager.h

 // Copyright 2014 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 ATHENA_VIRTUAL_KEYBOARD_PUBLIC_VIRTUAL_KEYBOARD_MANAGER_H_
 #define ATHENA_VIRTUAL_KEYBOARD_PUBLIC_VIRTUAL_KEYBOARD_MANAGER_H_
 
-#include "athena/athena_export.h"
+#include "athena/common/athena_export.h"
 
 namespace aura {
 class Window;
 }
 
 namespace content {
 class BrowserContext;
 }
 
 namespace athena {
 
 class ATHENA_EXPORT VirtualKeyboardManager {
  public:
   static VirtualKeyboardManager* Create(content::BrowserContext* context);
   static VirtualKeyboardManager* Get();
   static void Shutdown();
 };
 
 }  // namespace athena
 
 #endif  // ATHENA_VIRTUAL_KEYBOARD_PUBLIC_VIRTUAL_KEYBOARD_MANAGER_H_