Failure in reading Blob URL should results in network error

storage/browser/blob/blob_url_request_job.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 STORAGE_BROWSER_BLOB_BLOB_URL_REQUEST_JOB_H_
 #define STORAGE_BROWSER_BLOB_BLOB_URL_REQUEST_JOB_H_
 
 #include <stddef.h>
 
 #include <map>
@@ skipping 44 matching lines @@
   // Helper method to create the HTTP headers for the response.
   // |blob_handles|, |blob_reader|, |byte_range| and |content_size| are only
   // used if status_code isn't an error.
   static scoped_refptr<net::HttpResponseHeaders> GenerateHeaders(
       net::HttpStatusCode status_code,
       BlobDataHandle* blob_handle,
       BlobReader* blob_reader,
       net::HttpByteRange* byte_range,
       int64_t* content_size);
 
-  // Helper method to map from a net error to an http status code.
-  static net::HttpStatusCode NetErrorToHttpStatusCode(int error_code);
-
  protected:
   ~BlobURLRequestJob() override;
 
  private:
   typedef std::map<size_t, FileStreamReader*> IndexToReaderMap;
 
   // For preparing for read: get the size, apply the range and perform seek.
   void DidStart();
   void DidCalculateSize(int result);
   void DidReadMetadata(BlobReader::Status result);
@@ skipping 13 matching lines @@
   std::unique_ptr<net::HttpResponseInfo> response_info_;
 
   base::WeakPtrFactory<BlobURLRequestJob> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(BlobURLRequestJob);
 };
 
 }  // namespace storage
 
 #endif  // STORAGE_BROWSER_BLOB_BLOB_URL_REQUEST_JOB_H_