Add an identity (id) to system drag & drop.

webkit/glue/webview.h

 // Copyright (c) 2006-2008 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.
 
 #ifndef WEBKIT_GLUE_WEBVIEW_H__
 #define WEBKIT_GLUE_WEBVIEW_H__
 
 #include <string>
 #include <vector>
 
@@ skipping 167 matching lines @@
 
   // Callback methods when a drag and drop operation is trying to drop
   // something on the renderer.
   virtual bool DragTargetDragEnter(const WebDropData& drop_data,
       int client_x, int client_y, int screen_x, int screen_y) = 0;
   virtual bool DragTargetDragOver(
       int client_x, int client_y, int screen_x, int screen_y) = 0;
   virtual void DragTargetDragLeave() = 0;
   virtual void DragTargetDrop(
       int client_x, int client_y, int screen_x, int screen_y) = 0;
+  virtual int32 GetDragIdentity() = 0;
 
   // Notifies the webview that autofill suggestions are available for a node.
   virtual void AutofillSuggestionsForNode(
       int64 node_id,
       const std::vector<std::wstring>& suggestions,
       int default_suggestion_index) = 0;
 
  private:
   DISALLOW_EVIL_CONSTRUCTORS(WebView);
 };
 
 #endif  // WEBKIT_GLUE_WEBVIEW_H__