Make DownloadResourceThrottle robust to ContinueDownload being called before

chrome/browser/download/download_resource_throttle.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_RESOURCE_THROTTLE_H_
 #define CHROME_BROWSER_DOWNLOAD_DOWNLOAD_RESOURCE_THROTTLE_H_
 #pragma once
 
 #include "base/memory/weak_ptr.h"
 #include "chrome/browser/download/download_request_limiter.h"
@@ skipping 18 matching lines @@
                            int request_id);
 
   // content::ResourceThrottle implementation:
   virtual void WillStartRequest(bool* defer) OVERRIDE;
   virtual void WillRedirectRequest(const GURL& new_url, bool* defer) OVERRIDE;
   virtual void WillProcessResponse(bool* defer) OVERRIDE;
 
  private:
   virtual ~DownloadResourceThrottle();
 
+  void WillDownload(bool* defer);
   void ContinueDownload(bool allow);
 
+  // Set to true when we are querying the DownloadRequestLimiter.
+  bool querying_limiter_;
+
   // Set to true when we know that the request is allowed to start.
   bool request_allowed_;
 
   // Set to true when we have deferred the request.
   bool request_deferred_;
 
   DISALLOW_COPY_AND_ASSIGN(DownloadResourceThrottle);
 };
 
 #endif  // CHROME_BROWSER_DOWNLOAD_DOWNLOAD_RESOURCE_THROTTLE_H_