Clear the received slices in DownloadItemImpl when etag changed.

content/browser/download/mock_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_MOCK_DOWNLOAD_FILE_H_
 #define CONTENT_BROWSER_DOWNLOAD_MOCK_DOWNLOAD_FILE_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 10 matching lines @@
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace content {
 
 class MockDownloadFile : public DownloadFile {
  public:
   MockDownloadFile();
   virtual ~MockDownloadFile();
 
   // DownloadFile functions.
-  MOCK_METHOD1(Initialize, void(const InitializeCallback&));
+  MOCK_METHOD2(Initialize,
+               void(const InitializeCallback&,
+                    const DownloadItem::ReceivedSlices& received_slices));
   void AddByteStream(std::unique_ptr<ByteStreamReader> stream_reader,
                      int64_t offset,
                      int64_t length) override;
   MOCK_METHOD3(DoAddByteStream,
                void(ByteStreamReader* stream_reader,
                     int64_t offset,
                     int64_t length));
   MOCK_METHOD2(AppendDataToFile, DownloadInterruptReason(
       const char* data, size_t data_len));
   MOCK_METHOD1(Rename, DownloadInterruptReason(
@@ skipping 19 matching lines @@
   MOCK_METHOD1(GetHash, bool(std::string* hash));
   MOCK_METHOD0(SendUpdate, void());
   MOCK_CONST_METHOD0(Id, int());
   MOCK_METHOD0(GetDownloadManager, DownloadManager*());
   MOCK_CONST_METHOD0(DebugString, std::string());
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_DOWNLOAD_MOCK_DOWNLOAD_FILE_H_