Cleanup: Remove unneeded headers from app/

chrome/browser/bookmarks/bookmark_drag_data.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_BOOKMARKS_BOOKMARK_DRAG_DATA_H_
 #define CHROME_BROWSER_BOOKMARKS_BOOKMARK_DRAG_DATA_H_
 #pragma once
 
 #include <string>
 #include <vector>
 
 #include "base/file_path.h"
 #include "base/string16.h"
 #include "googleurl/src/gurl.h"
 
 #if defined(TOOLKIT_VIEWS)
 #include "app/os_exchange_data.h"
 #endif
 
 class BookmarkModel;
 class BookmarkNode;
-class OSExchangeData;
 class Pickle;
 class Profile;
 
 // TODO(mrossetti): Rename BookmarkDragData to BookmarkNodeData, update comment.
 // See: http://crbug.com/37891
 
 // BookmarkDragData is used to represent the following:
 //
 // . A single URL.
 // . A single node from the bookmark model.
@@ skipping 128 matching lines @@
   static const char* kClipboardFormatString;
 
   static bool ClipboardContainsBookmarks();
 
  private:
   // Path of the profile we originated from.
   FilePath::StringType profile_path_;
 };
 
 #endif  // CHROME_BROWSER_BOOKMARKS_BOOKMARK_DRAG_DATA_H_