Add glue for supporting custom MIME types in DataTransfer.

content/renderer/renderer_clipboard_client.h

Index: content/renderer/renderer_clipboard_client.h
diff --git a/content/renderer/renderer_clipboard_client.h b/content/renderer/renderer_clipboard_client.h
index df0ab074562b8cbc279484afa87a404834c899cc..f14b55e3ade2ddbe6ee63001747aa210b0ceb3b9 100644
--- a/content/renderer/renderer_clipboard_client.h
+++ b/content/renderer/renderer_clipboard_client.h
@@ -30,6 +30,9 @@ class RendererClipboardClient : public webkit_glue::ClipboardClient {
                         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);

[tony, 2011/12/02 00:13:29]

Nit: OVERRIDE like the other methods?

[dcheng, 2011/12/02 00:29:17]

Done.

   virtual WriteContext* CreateWriteContext() OVERRIDE;
 };