Switch BookmarkTabHelper to use WebContentsUserData.

chrome/browser/tab_contents/web_drag_bookmark_handler_mac.h

 // Copyright (c) 2012 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_WEB_DRAG_BOOKMARK_HANDLER_MAC_H_
 #define CHROME_BROWSER_TAB_CONTENTS_WEB_DRAG_BOOKMARK_HANDLER_MAC_H_
 
 #include "base/compiler_specific.h"
 #include "chrome/browser/bookmarks/bookmark_node_data.h"
 #include "content/public/browser/web_drag_dest_delegate.h"
 
-class TabContents;
+class BookmarkTabHelper;
+
+namespace content {
+class WebContents;
+}
 
 // Chrome needs to intercept content drag events so it can dispatch them to the
 // bookmarks and extensions system.
 class WebDragBookmarkHandlerMac : public content::WebDragDestDelegate {
  public:
   WebDragBookmarkHandlerMac();
   virtual ~WebDragBookmarkHandlerMac();
 
   // Overridden from content::WebDragDestDelegate:
   virtual void DragInitialize(content::WebContents* contents) OVERRIDE;
   virtual void OnDragOver() OVERRIDE;
   virtual void OnDragEnter() OVERRIDE;
   virtual void OnDrop() OVERRIDE;
   virtual void OnDragLeave() OVERRIDE;
 
  private:
-  // The TabContents.
-  // Weak reference; may be NULL if the contents aren't contained in a
-  // TabContents (e.g. WebUI dialogs).
-  TabContents* tab_;
+  // The BookmarkTabHelper.
+  // Weak reference; may be NULL if the contents don't have a
+  // BookmarkTabHelper (e.g. WebUI dialogs).
+  BookmarkTabHelper* bookmark_tab_helper_;
+
+  content::WebContents* web_contents_;
 
   // The bookmark data for the current tab. This will be empty if there is not
   // a native bookmark drag.
   BookmarkNodeData bookmark_drag_data_;
 
   DISALLOW_COPY_AND_ASSIGN(WebDragBookmarkHandlerMac);
 };
 
 #endif  // CHROME_BROWSER_TAB_CONTENTS_WEB_DRAG_BOOKMARK_HANDLER_MAC_H_