GTK: implement extension bookmark manager drag api....

chrome/browser/gtk/download_item_drag.h

-// Copyright (c) 2010 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_GTK_DOWNLOAD_ITEM_DRAG_H_
-#define CHROME_BROWSER_GTK_DOWNLOAD_ITEM_DRAG_H_
-
-#include <gtk/gtk.h>
-
-#include "base/basictypes.h"
-
-class DownloadItem;
-class SkBitmap;
-
-class DownloadItemDrag {
- public:
-  // Sets |widget| as a source for drags pertaining to |item|. No
-  // DownloadItemDrag object is created.
-  static void SetSource(GtkWidget* widget, DownloadItem* item);
-
-  // Creates a new DownloadItemDrag, the lifetime of which is tied to the
-  // system drag.
-  static void BeginDrag(const DownloadItem* item, SkBitmap* icon);
-
- private:
-  explicit DownloadItemDrag(const DownloadItem* item, SkBitmap* icon);
-  ~DownloadItemDrag();
-
-  static void OnDragBegin(GtkWidget* widget,
-                          GdkDragContext* drag_context,
-                          DownloadItemDrag* drag);
-
-  static void OnDragEnd(GtkWidget* widget,
-                        GdkDragContext* drag_context,
-                        DownloadItemDrag* drag);
-
-  GtkWidget* drag_widget_;
-  GdkPixbuf* pixbuf_;
-
-  DISALLOW_COPY_AND_ASSIGN(DownloadItemDrag);
-};
-
-#endif  // CHROME_BROWSER_GTK_DOWNLOAD_ITEM_DRAG_H_