[Downloads] Do not store error responses during resumption.

content/browser/download/url_downloader.cc

 // Copyright 2015 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.
 
 #include "content/browser/download/url_downloader.h"
 
 #include "base/callback_helpers.h"
 #include "base/location.h"
 #include "base/macros.h"
 #include "base/threading/sequenced_task_runner_handle.h"
@@ skipping 98 matching lines @@
     return;
 
   request_->set_delegate(this);
   request_->Start();
 }
 
 void UrlDownloader::OnReceivedRedirect(net::URLRequest* request,
                                        const net::RedirectInfo& redirect_info,
                                        bool* defer_redirect) {
   DVLOG(1) << "OnReceivedRedirect: " << request_->url().spec();
-  request_->CancelWithError(net::ERR_ABORTED);
+
+  // We are going to block redirects even if DownloadRequestCore allows it.  No
+  // redirects are expected for download requests that are made without a
+  // renderer, which are currently exclusively resumption requests. Since there
+  // is no security policy being applied here, it's safer to block redirects and
+  // revisit if some previously unknown legitimate use case arises for redirects
+  // while resuming.
+  core_.OnWillAbort(DOWNLOAD_INTERRUPT_REASON_SERVER_UNREACHABLE);
+  request_->CancelWithError(net::ERR_UNSAFE_REDIRECT);
 }
 
 void UrlDownloader::OnResponseStarted(net::URLRequest* request) {
   DVLOG(1) << "OnResponseStarted: " << request_->url().spec();
 
   if (!request_->status().is_success()) {
     ResponseCompleted();
     return;
   }
 
@@ skipping 112 matching lines @@
   Destroy();
 }
 
 void UrlDownloader::Destroy() {
   BrowserThread::PostTask(
       BrowserThread::UI, FROM_HERE,
       base::Bind(&DownloadManagerImpl::RemoveUrlDownloader, manager_, this));
 }
 
 }  // namespace content