Add glue for supporting custom MIME types in DataTransfer.

webkit/glue/webdropdata.h

Index: webkit/glue/webdropdata.h
diff --git a/webkit/glue/webdropdata.h b/webkit/glue/webdropdata.h
index a9a4ae76c366b93373d93b807e4e57cc1fddb303..844a435593a4990bfbecd9187abc2310ca2b3704 100644
--- a/webkit/glue/webdropdata.h
+++ b/webkit/glue/webdropdata.h
@@ -9,6 +9,7 @@
 #ifndef WEBKIT_GLUE_WEBDROPDATA_H_
 #define WEBKIT_GLUE_WEBDROPDATA_H_
 
+#include <map>
 #include <string>
 #include <vector>
 
@@ -55,6 +56,8 @@ struct WebDropData {
   string16 file_description_filename;
   std::string file_contents;
 
+  std::map<string16, string16> custom_data;

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

Hmm, I guess since the API is from javascript, there's no easy way to put bytes
into the clipboard for other apps to consume.  That seems like a pretty big
limitation of custom data types, but I guess that can be addressed in future
versions of the spec?

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

Given the APIs available on Windows/Linux, we can't safely expose those APIs to
the web, even with attempts to set a limit of x per domain, since these
resources aren't reclaimable. It's definitely not ideal, hopefully the native
APIs improve.

+
   // Convert to a WebDragData object.
   WebKit::WebDragData ToDragData() const;