Clear the received slices in DownloadItemImpl when etag changed.

content/browser/download/download_file.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_BROWSER_DOWNLOAD_DOWNLOAD_FILE_H_
 #define CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_FILE_H_
 
 #include <stdint.h>
 
 #include <memory>
 #include <string>
 
 #include "base/callback_forward.h"
 #include "base/files/file_path.h"
 #include "content/common/content_export.h"
 #include "content/public/browser/download_interrupt_reasons.h"
+#include "content/public/browser/download_item.h"
 
 class GURL;
 
 namespace content {
 
 class ByteStreamReader;
 
 // These objects live exclusively on the file thread and handle the writing
 // operations for one download. These objects live only for the duration that
 // the download is 'in progress': once the download has been completed or
@@ skipping 12 matching lines @@
   // error.
   typedef base::Callback<void(DownloadInterruptReason reason,
                               const base::FilePath& path)>
       RenameCompletionCallback;
 
   virtual ~DownloadFile() {}
 
   // Upon completion, |callback| will be called on the UI
   // thread as per the comment above, passing DOWNLOAD_INTERRUPT_REASON_NONE
   // on success, or a network download interrupt reason on failure.
-  virtual void Initialize(const InitializeCallback& callback) = 0;
+  virtual void Initialize(
+      const InitializeCallback& callback,
+      const DownloadItem::ReceivedSlices& received_slices) = 0;
 
   // Add a byte stream reader to write into a slice of the file, used for
   // parallel download. Called on the file thread.
   virtual void AddByteStream(std::unique_ptr<ByteStreamReader> stream_reader,
                              int64_t offset,
                              int64_t length) = 0;
 
   // Rename the download file to |full_path|.  If that file exists
   // |full_path| will be uniquified by suffixing " (<number>)" to the
   // file name before the extension.
@@ skipping 24 matching lines @@
   virtual void SetPotentialFileLength(int64_t length) = 0;
 
   virtual const base::FilePath& FullPath() const = 0;
   virtual bool InProgress() const = 0;
   virtual void WasPaused() = 0;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_FILE_H_