Handle early pause, cancel for parallel requests.

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"
 #include "base/memory/weak_ptr.h"
 #include "content/browser/byte_stream.h"
 #include "content/browser/download/download_request_handle.h"
 #include "content/browser/download/url_downloader.h"
+#include "content/common/content_export.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/download_url_parameters.h"
 
 namespace content {
 
 // Helper class used to send subsequent range requests to fetch slices of the
 // file after handling response of the original non-range request.
 // TODO(xingliu): we should consider to reuse this class for single connection
 // download.
-class DownloadWorker : public UrlDownloader::Delegate {
+class CONTENT_EXPORT 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;
+    virtual bool IsPaused() const = 0;
+    virtual bool IsCanceled() const = 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 33 matching lines @@
       url_downloader_;
 
   base::WeakPtrFactory<DownloadWorker> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(DownloadWorker);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_WORKER_H_