[XHR] Ignore didReceiveData when having a DataConsumerHandle.

Source/core/loader/DocumentThreadableLoader.h

 /*
  * Copyright (C) 2009, 2012 Google Inc. All rights reserved.
  * Copyright (C) 2013, Intel Corporation
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
@@ skipping 123 matching lines @@
         bool m_forceDoNotAllowStoredCredentials;
         RefPtr<SecurityOrigin> m_securityOrigin;
 
         // True while the initial URL and all the URLs of the redirects
         // this object has followed, if any, are same-origin to
         // securityOrigin().
         bool m_sameOriginRequest;
         // Set to true if the current request is cross-origin and not simple.
         bool m_crossOriginNonSimpleRequest;
 
+        // Set to true when the response data is given to a data consumer
+        // handle.
+        bool m_isUsingDataConsumerHandle;
+
         const bool m_async;
 
         // Holds the original request context (used for sanity checks).
         const WebURLRequest::RequestContext m_requestContext;
 
         // Holds the original request for fallback in case the Service Worker
         // does not respond.
         OwnPtr<ResourceRequest> m_fallbackRequestForServiceWorker;
 
         // Holds the original request and options for it during preflight
         // request handling phase.
         OwnPtr<ResourceRequest> m_actualRequest;
         OwnPtr<ResourceLoaderOptions> m_actualOptions;
 
         HTTPHeaderMap m_simpleRequestHeaders; // stores simple request headers in case of a cross-origin redirect.
         Timer<DocumentThreadableLoader> m_timeoutTimer;
         double m_requestStartedSeconds; // Time an asynchronous fetch request is started
 
         // Max number of times that this DocumentThreadableLoader can follow
         // cross-origin redirects.
         // This is used to limit the number of redirects.
         // But this value is not the max number of total redirects allowed,
         // because same-origin redirects are not counted here.
         int m_corsRedirectLimit;
     };
 
 } // namespace blink
 
 #endif // DocumentThreadableLoader_h