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

chrome/browser/tab_contents/tab_contents_view_gtk.h

 // Copyright (c) 2009 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 CHROME_BROWSER_TAB_CONTENTS_TAB_CONTENTS_VIEW_GTK_H_
 #define CHROME_BROWSER_TAB_CONTENTS_TAB_CONTENTS_VIEW_GTK_H_
 
 #include <gtk/gtk.h>
 
 #include <vector>
@@ skipping 48 matching lines @@
   virtual void SetPageTitle(const std::wstring& title);
   virtual void OnTabCrashed();
   virtual void SizeContents(const gfx::Size& size);
   virtual void Focus();
   virtual void SetInitialFocus();
   virtual void StoreFocus();
   virtual void RestoreFocus();
 
   // Backend implementation of RenderViewHostDelegate::View.
   virtual void ShowContextMenu(const ContextMenuParams& params);
-  virtual void StartDragging(const WebDropData& drop_data);
-  virtual void UpdateDragCursor(bool is_drop_target);
+  virtual void StartDragging(const WebDropData& drop_data,
+                             WebKit::WebDragOperationsMask allowed_ops);
+  virtual void UpdateDragCursor(WebKit::WebDragOperation operation);
   virtual void GotFocus();
   virtual void TakeFocus(bool reverse);
   virtual void HandleKeyboardEvent(const NativeWebKeyboardEvent& event);
 
   // NotificationObserver implementation ---------------------------------------
 
   virtual void Observe(NotificationType type,
                        const NotificationSource& source,
                        const NotificationDetails& details);
 
@@ skipping 54 matching lines @@
   // GTK.
   scoped_ptr<WebDragDest> drag_dest_;
 
   // Object responsible for handling drags from the page for us.
   scoped_ptr<TabContentsDragSource> drag_source_;
 
   DISALLOW_COPY_AND_ASSIGN(TabContentsViewGtk);
 };
 
 #endif  // CHROME_BROWSER_TAB_CONTENTS_TAB_CONTENTS_VIEW_GTK_H_