Add stubs and glue for routing a request for an image from the clipboard.

ui/base/clipboard/clipboard_linux.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.
 
 #include "ui/base/clipboard/clipboard.h"
 
 #include <gtk/gtk.h>
 #include <map>
 #include <set>
 #include <string>
@@ skipping 342 matching lines @@
     UTF8ToUTF16(reinterpret_cast<char*>(data->data), data->length, markup);
   }
 
   // If there is a terminating NULL, drop it.
   if (!markup->empty() && markup->at(markup->length() - 1) == '\0')
     markup->resize(markup->length() - 1);
 
   gtk_selection_data_free(data);
 }
 
+void Clipboard::ReadImage(Buffer buffer, std::string* data) const {
+  // TODO(dcheng): implement this.
+  NOTIMPLEMENTED();
+  if (!data) {
+    NOTREACHED();
+    return;
+  }
+}
+
 void Clipboard::ReadBookmark(string16* title, std::string* url) const {
   // TODO(estade): implement this.
   NOTIMPLEMENTED();
 }
 
 void Clipboard::ReadData(const std::string& format, std::string* result) {
   GtkSelectionData* data =
       gtk_clipboard_wait_for_contents(clipboard_, StringToGdkAtom(format));
   if (!data)
     return;
@@ skipping 39 matching lines @@
       return clipboard_;
     case BUFFER_SELECTION:
       return primary_selection_;
     default:
       NOTREACHED();
       return NULL;
   }
 }
 
 }  // namespace ui