Plumb the DragOperation through all the layers between the platform DnD code ...

chrome/common/webkit_param_traits.h

Index: chrome/common/webkit_param_traits.h
===================================================================
--- chrome/common/webkit_param_traits.h	(revision 25321)
+++ chrome/common/webkit_param_traits.h	(working copy)
@@ -27,6 +27,7 @@
 #include "webkit/api/public/WebCache.h"
 #include "webkit/api/public/WebCompositionCommand.h"
 #include "webkit/api/public/WebConsoleMessage.h"
+#include "webkit/api/public/WebDragOperation.h"
 #include "webkit/api/public/WebFindOptions.h"
 #include "webkit/api/public/WebInputEvent.h"
 #include "webkit/api/public/WebScreenInfo.h"
@@ -302,6 +303,23 @@
   }
 };
 
+template <>
+  struct ParamTraits<WebKit::WebDragOperation> {
+  typedef WebKit::WebDragOperation param_type;
+  static void Write(Message* m, const param_type& p) {
+    m->WriteInt(p);
+  }
+  static bool Read(const Message* m, void** iter, param_type* r) {
+    int temp;
+    bool res = m->ReadInt(iter, &temp);
+    *r = static_cast<param_type>(temp);
+    return res;
+  }
+  static void Log(const param_type& p, std::wstring* l) {
+    l->append(StringPrintf(L"%d", p));
+  }
+};
+
 }  // namespace IPC
 
 #endif  // CHROME_COMMON_WEBKIT_PARAM_TRAITS_H_