move file access permission logic to DownloadResourceThrottle

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_
 
 #include "base/memory/weak_ptr.h"
 #include "chrome/browser/download/download_request_limiter.h"
 #include "content/public/browser/resource_throttle.h"
 
 class GURL;
 
 // DownloadResourceThrottle is used to determine if a download should be
 // allowed. When a DownloadResourceThrottle is created it pauses the download
 // and asks the DownloadRequestLimiter if the download should be allowed. The
 // DownloadRequestLimiter notifies us asynchronously as to whether the download
 // is allowed or not. If the download is allowed the request is resumed.  If
 // the download is not allowed the request is canceled.
 
 class DownloadResourceThrottle
     : public content::ResourceThrottle,
       public base::SupportsWeakPtr<DownloadResourceThrottle> {
  public:
-  DownloadResourceThrottle(DownloadRequestLimiter* limiter,
+  // Information passed between callbacks to check whether download can proceed.
+  struct DownloadRequestInfo {
+    DownloadRequestInfo(
+        scoped_refptr<DownloadRequestLimiter> limiter,
+        int render_process_id,
+        int render_view_id,
+        const GURL& url,
+        const std::string& request_method,
+        const DownloadRequestLimiter::Callback& continue_callback);
+    ~DownloadRequestInfo();
+
+    scoped_refptr<DownloadRequestLimiter> limiter;
+    int render_process_id;
+    int render_view_id;
+    GURL url;
+    std::string request_method;
+    DownloadRequestLimiter::Callback continue_callback;
+   private:
+    DISALLOW_COPY_AND_ASSIGN(DownloadRequestInfo);
+  };
+
+  DownloadResourceThrottle(scoped_refptr<DownloadRequestLimiter> limiter,
                            int render_process_id,
                            int render_view_id,
                            const GURL& url,
                            const std::string& request_method);
 
   // content::ResourceThrottle implementation:
   void WillStartRequest(bool* defer) override;
   void WillRedirectRequest(const net::RedirectInfo& redirect_info,
                            bool* defer) override;
   void WillProcessResponse(bool* defer) override;
   const char* GetNameForLogging() const override;
 
+  void ContinueDownload(bool allow);
+
  private:
   ~DownloadResourceThrottle() override;
 
   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_