Make Clipboard::FormatType an opaque handle type.

ui/base/clipboard/scoped_clipboard_writer.cc

 // 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.
 
 // This file implements the ScopedClipboardWriter class. Documentation on its
 // purpose can be found in our header. Documentation on the format of the
 // parameters for each clipboard target can be found in clipboard.h.
 
 #include "ui/base/clipboard/scoped_clipboard_writer.h"
 
@@ skipping 86 matching lines @@
   size_t size_length = sizeof(gfx::Size);
   for (size_t i = 0; i < size_length; i++)
     size_parameter.push_back(size_data[i]);
 
   Clipboard::ObjectMapParams parameters;
   parameters.push_back(pixels_parameter);
   parameters.push_back(size_parameter);
   objects_[Clipboard::CBF_BITMAP] = parameters;
 }
 
-void ScopedClipboardWriter::WritePickledData(const Pickle& pickle,
-                                             Clipboard::FormatType format) {
-  Clipboard::ObjectMapParam format_parameter(format.begin(), format.end());
+void ScopedClipboardWriter::WritePickledData(
+    const Pickle& pickle, const Clipboard::FormatType& format) {
+  std::string format_string = format.Serialize();
+  Clipboard::ObjectMapParam format_parameter(format_string.begin(),
+                                             format_string.end());
   Clipboard::ObjectMapParam data_parameter;
 
   data_parameter.resize(pickle.size());
   memcpy(const_cast<char*>(&data_parameter.front()),
          pickle.data(), pickle.size());
 
   Clipboard::ObjectMapParams parameters;
   parameters.push_back(format_parameter);
   parameters.push_back(data_parameter);
   objects_[Clipboard::CBF_DATA] = parameters;
@@ skipping 11 matching lines @@
   objects_[Clipboard::CBF_TEXT] = parameters;
 
   if (is_url) {
     url_text_ = utf8_text;
   } else {
     url_text_.clear();
   }
 }
 
 }  // namespace ui