Add glue for supporting custom MIME types in DataTransfer.

webkit/tools/test_shell/simple_clipboard_impl.h

 // Copyright (c) 2011 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 WEBKIT_TOOLS_TEST_SHELL_SIMPLE_CLIPBOARD_IMPL_H_
 #define WEBKIT_TOOLS_TEST_SHELL_SIMPLE_CLIPBOARD_IMPL_H_
 
 #include "base/compiler_specific.h"
 #include "webkit/glue/clipboard_client.h"
 
@@ skipping 11 matching lines @@
                                   bool* contains_filenames) OVERRIDE;
   virtual void ReadText(ui::Clipboard::Buffer buffer,
                         string16* result) OVERRIDE;
   virtual void ReadAsciiText(ui::Clipboard::Buffer buffer,
                              std::string* result) OVERRIDE;
   virtual void ReadHTML(ui::Clipboard::Buffer buffer, string16* markup,
                         GURL* url, uint32* fragment_start,
                         uint32* fragment_end) OVERRIDE;
   virtual void ReadImage(ui::Clipboard::Buffer buffer,
                          std::string* data) OVERRIDE;
+  virtual void ReadCustomData(ui::Clipboard::Buffer buffer,
+                              const string16& type,
+                              string16* data) OVERRIDE;
   virtual WriteContext* CreateWriteContext() OVERRIDE;
 };
 
 #endif  // WEBKIT_TOOLS_TEST_SHELL_SIMPLE_CLIPBOARD_IMPL_H_