chrome: Cleanup class/struct forward declarations

chrome/browser/download/download_file_picker.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_DOWNLOAD_DOWNLOAD_FILE_PICKER_H_
 #define CHROME_BROWSER_DOWNLOAD_DOWNLOAD_FILE_PICKER_H_
 
 #include "base/callback.h"
 #include "base/macros.h"
 #include "ui/shell_dialogs/select_file_dialog.h"
 
 namespace base {
 class FilePath;
 }
 
 namespace content {
 class DownloadItem;
-class DownloadManager;
-class WebContents;
 }
 
 // Handles showing a dialog to the user to ask for the filename for a download.
 class DownloadFilePicker : public ui::SelectFileDialog::Listener {
  public:
   // Callback used to pass the user selection back to the owner of this
   // object.
   // |virtual_path|: The path chosen by the user. If the user cancels the file
   //    selection, then this parameter will be the empty path. On Chrome OS,
   //    this path may contain virtual mount points if the user chose a virtual
@@ skipping 34 matching lines @@
   scoped_refptr<ui::SelectFileDialog> select_file_dialog_;
 
   // True if UMA regarding on the result of the file selection should be
   // recorded.
   bool should_record_file_picker_result_;
 
   DISALLOW_COPY_AND_ASSIGN(DownloadFilePicker);
 };
 
 #endif  // CHROME_BROWSER_DOWNLOAD_DOWNLOAD_FILE_PICKER_H_