Add flag to specify if explicitly requested download is from web.

content/public/browser/resource_dispatcher_host.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 CONTENT_PUBLIC_BROWSER_RESOURCE_DISPATCHER_HOST_H_
 #define CONTENT_PUBLIC_BROWSER_RESOURCE_DISPATCHER_HOST_H_
 #pragma once
 
 #include "base/callback_forward.h"
 #include "content/public/browser/download_id.h"
@@ skipping 19 matching lines @@
   // delegate have a longer lifetime than the ResourceDispatcherHost.
   virtual void SetDelegate(ResourceDispatcherHostDelegate* delegate) = 0;
 
   // Controls whether third-party sub-content can pop-up HTTP basic auth
   // dialog boxes.
   virtual void SetAllowCrossOriginAuthPrompt(bool value) = 0;
 
   // Initiates a download by explicit request of the renderer, e.g. due to
   // alt-clicking a link.  If the download is started, |started_callback| will
   // be called on the UI thread with the DownloadId; otherwise an error code
-  // will be returned.
+  // will be returned.  |is_content_initiated| is used to indicate that
+  // the request was generated from a web page, and hence may not be
+  // as trustworthy as a browser generated request.
   virtual net::Error BeginDownload(
       scoped_ptr<net::URLRequest> request,
+      bool is_content_initiated,
       ResourceContext* context,
       int child_id,
       int route_id,
       bool prefer_cache,
       const DownloadSaveInfo& save_info,
       const DownloadStartedCallback& started_callback) = 0;
 
   // Clears the ResourceDispatcherHostLoginDelegate associated with the request.
   virtual void ClearLoginDelegateForRequest(net::URLRequest* request) = 0;
 
   // Marks the request as "parked". This happens if a request is
   // redirected cross-site and needs to be resumed by a new render view.
   virtual void MarkAsTransferredNavigation(net::URLRequest* request) = 0;
 
  protected:
   virtual ~ResourceDispatcherHost() {}
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_RESOURCE_DISPATCHER_HOST_H_