chrome: Cleanup class/struct forward declarations

chrome/browser/download/download_danger_prompt.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_DANGER_PROMPT_H_
 #define CHROME_BROWSER_DOWNLOAD_DOWNLOAD_DANGER_PROMPT_H_
 
 #include "base/callback_forward.h"
 #include "chrome/common/safe_browsing/csd.pb.h"
 
-class GURL;
-
 namespace content {
 class DownloadItem;
 class WebContents;
 }
 
 // Prompts the user for whether to Keep a dangerous DownloadItem using native
 // UI. This prompt is invoked by the DownloadsDOMHandler when the user wants to
 // accept a dangerous download. Having a native dialog intervene during the this
 // workflow means that the chrome://downloads page no longer has the privilege
 // to accept a dangerous download from script without user intervention. This
@@ skipping 40 matching lines @@
       bool did_proceed,
       const content::DownloadItem& download);
 
  protected:
   // Records UMA stats for a download danger prompt event.
   static void RecordDownloadDangerPrompt(bool did_proceed,
                                          const content::DownloadItem& download);
 };
 
 #endif  // CHROME_BROWSER_DOWNLOAD_DOWNLOAD_DANGER_PROMPT_H_