Propagate server response error and interrupt the download.

content/browser/download/download_worker.h

 // Copyright 2017 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_BROWSER_DOWNLOAD_DOWNLOAD_WORKER_H_
 #define CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_WORKER_H_
 
 #include <memory>
 
 #include "base/macros.h"
@@ skipping 13 matching lines @@
 class DownloadWorker : public UrlDownloader::Delegate {
  public:
   class Delegate {
    public:
     // Called when the the byte stream is established after server response is
     // handled. The stream contains data starts from |offset| of the
     // destination file.
     virtual void OnByteStreamReady(
         DownloadWorker* worker,
         std::unique_ptr<ByteStreamReader> stream_reader) = 0;
+    // Called when there is an error caused by the server response.
+    virtual void OnServerResponseError(DownloadWorker* worker,
+                                       DownloadInterruptReason reason) = 0;
   };
 
   DownloadWorker(DownloadWorker::Delegate* delegate,
                  int64_t offset,
                  int64_t length);
   virtual ~DownloadWorker();
 
   int64_t offset() const { return offset_; }
   int64_t length() const { return length_; }
 
@@ skipping 10 matching lines @@
   void OnUrlDownloaderStarted(
       std::unique_ptr<DownloadCreateInfo> create_info,
       std::unique_ptr<ByteStreamReader> stream_reader,
       const DownloadUrlParameters::OnStartedCallback& callback) override;
   void OnUrlDownloaderStopped(UrlDownloader* downloader) override;
 
   void AddUrlDownloader(
       std::unique_ptr<UrlDownloader, BrowserThread::DeleteOnIOThread>
           downloader);
 
-  DownloadWorker::Delegate* delegate_;
+  DownloadWorker::Delegate* const delegate_;
 
   // The starting position of the content for this worker to download.
   int64_t offset_;
 
   // The length of the request. May be 0 to fetch to the end of the file.
   int64_t length_;
 
   // Used to control the network request. Live on UI thread.
   std::unique_ptr<DownloadRequestHandleInterface> request_handle_;
 
   // Used to handle the url request. Live and die on IO thread.
   std::unique_ptr<UrlDownloader, BrowserThread::DeleteOnIOThread>
       url_downloader_;
 
   base::WeakPtrFactory<DownloadWorker> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DownloadWorker);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_WORKER_H_