Use downloadToFile option when XHR downloads a Blob

Source/core/fetch/ResourceLoader.cpp

 /*
  * Copyright (C) 2006, 2007, 2010, 2011 Apple Inc. All rights reserved.
  *           (C) 2007 Graham Dennis (graham.dennis@gmail.com)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 152 matching lines @@
         m_request = m_deferredRequest;
         m_deferredRequest = ResourceRequest();
         start();
     }
 }
 
 void ResourceLoader::didDownloadData(WebKit::WebURLLoader*, int length, int encodedDataLength)
 {
     RefPtr<ResourceLoader> protect(this);
     RELEASE_ASSERT(m_connectionState == ConnectionStateReceivedResponse);
+    m_host->didDownloadData(m_resource, length, encodedDataLength, m_options);
     m_resource->didDownloadData(length);
 }
 
 void ResourceLoader::didFinishLoadingOnePart(double finishTime)
 {
     // If load has been cancelled after finishing (which could happen with a
     // JavaScript that changes the window location), do nothing.
     if (m_state == Terminated)
         return;
 
@@ skipping 229 matching lines @@
         return;
     }
     didReceiveResponse(0, responseOut);
     RefPtr<ResourceLoadInfo> resourceLoadInfo = responseOut.toResourceResponse().resourceLoadInfo();
     m_host->didReceiveData(m_resource, dataOut.data(), dataOut.size(), resourceLoadInfo ? resourceLoadInfo->encodedDataLength : -1, m_options);
     m_resource->setResourceBuffer(dataOut);
     didFinishLoading(0, responseOut.responseTime());
 }
 
 }