Delete the GTK+ port of Chrome.

ui/base/dragdrop/os_exchange_data.h

 // 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.
 
 #ifndef UI_BASE_DRAGDROP_OS_EXCHANGE_DATA_H_
 #define UI_BASE_DRAGDROP_OS_EXCHANGE_DATA_H_
 
 #include "build/build_config.h"
 
 #include <set>
 #include <string>
 
 #if defined(OS_WIN)
 #include <objidl.h>
-#elif defined(TOOLKIT_GTK)
-#include <gtk/gtk.h>
 #endif
 
 #include "base/basictypes.h"
 #include "base/files/file_path.h"
 #include "base/memory/scoped_ptr.h"
 #include "ui/base/clipboard/clipboard.h"
 #include "ui/base/dragdrop/download_file_interface.h"
 #include "ui/base/ui_base_export.h"
 
 class GURL;
@@ skipping 206 matching lines @@
  private:
   // Provides the actual data.
   scoped_ptr<Provider> provider_;
 
   DISALLOW_COPY_AND_ASSIGN(OSExchangeData);
 };
 
 }  // namespace ui
 
 #endif  // UI_BASE_DRAGDROP_OS_EXCHANGE_DATA_H_