Revert of [XMLHttpRequest] Stop throwing for network error in async mode

Source/core/xmlhttprequest/XMLHttpRequest.cpp

 /*
  *  Copyright (C) 2004, 2006, 2008 Apple Inc. All rights reserved.
  *  Copyright (C) 2005-2007 Alexey Proskuryakov <ap@webkit.org>
  *  Copyright (C) 2007, 2008 Julien Chaffraix <jchaffraix@webkit.org>
  *  Copyright (C) 2008, 2011 Google Inc. All rights reserved.
  *  Copyright (C) 2012 Intel Corporation
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Lesser General Public
  *  License as published by the Free Software Foundation; either
@@ skipping 819 matching lines @@
 
     createRequest(httpBody.release(), exceptionState);
 }
 
 void XMLHttpRequest::sendForInspectorXHRReplay(PassRefPtr<FormData> formData, ExceptionState& exceptionState)
 {
     createRequest(formData ? formData->deepCopy() : nullptr, exceptionState);
     m_exceptionCode = exceptionState.code();
 }
 
-void XMLHttpRequest::throwForLoadFailureIfNeeded(ExceptionState& exceptionState, const String& reason)
-{
-    if (m_error && !m_exceptionCode)
-        m_exceptionCode = NetworkError;
-
-    if (!m_exceptionCode)
-        return;
-
-    String message = "Failed to load '" + m_url.elidedString() + "'";
-    if (reason.isNull()) {
-        message.append(".");
-    } else {
-        message.append(": ");
-        message.append(reason);
-    }
-
-    exceptionState.throwDOMException(m_exceptionCode, message);
-}
-
 void XMLHttpRequest::createRequest(PassRefPtr<FormData> httpBody, ExceptionState& exceptionState)
 {
     // Only GET request is supported for blob URL.
     if (m_url.protocolIs("blob") && m_method != "GET") {
-        handleNetworkError();
-
-        if (!m_async) {
-            throwForLoadFailureIfNeeded(exceptionState, "'GET' is the only method allowed for 'blob:' URLs.");
-        }
+        exceptionState.throwDOMException(NetworkError, "'GET' is the only method allowed for 'blob:' URLs.");
         return;
     }
 
     // The presence of upload event listeners forces us to use preflighting because POSTing to an URL that does not
     // permit cross origin requests should look exactly like POSTing to an URL that does not respond at all.
     // Also, only async requests support upload progress events.
     bool uploadEvents = false;
     if (m_async) {
         dispatchProgressEvent(EventTypeNames::loadstart, 0, 0);
         if (httpBody && m_upload) {
@@ skipping 54 matching lines @@
         UseCounter::count(&executionContext, UseCounter::XMLHttpRequestAsynchronous);
         if (m_upload)
             request.setReportUploadProgress(true);
 
         // ThreadableLoader::create can return null here, for example if we're no longer attached to a page.
         // This is true while running onunload handlers.
         // FIXME: Maybe we need to be able to send XMLHttpRequests from onunload, <http://bugs.webkit.org/show_bug.cgi?id=10904>.
         // FIXME: Maybe create() can return null for other reasons too?
         ASSERT(!m_loader);
         m_loader = ThreadableLoader::create(executionContext, this, request, options, resourceLoaderOptions);
-
-        return;
+    } else {
+        // Use count for XHR synchronous requests.
+        UseCounter::count(&executionContext, UseCounter::XMLHttpRequestSynchronous);
+        ThreadableLoader::loadResourceSynchronously(executionContext, request, *this, options, resourceLoaderOptions);
     }
 
-    // Use count for XHR synchronous requests.
-    UseCounter::count(&executionContext, UseCounter::XMLHttpRequestSynchronous);
-    ThreadableLoader::loadResourceSynchronously(executionContext, request, *this, options, resourceLoaderOptions);
-
-    throwForLoadFailureIfNeeded(exceptionState, String());
+    if (!m_exceptionCode && m_error)
+        m_exceptionCode = NetworkError;
+    if (m_exceptionCode)
+        exceptionState.throwDOMException(m_exceptionCode, "Failed to load '" + m_url.elidedString() + "'.");
 }
 
 void XMLHttpRequest::abort()
 {
     WTF_LOG(Network, "XMLHttpRequest %p abort()", this);
 
     // internalAbort() clears |m_loader|. Compute |sendFlag| now.
     //
     // |sendFlag| corresponds to "the send() flag" defined in the XHR spec.
     //
@@ skipping 732 matching lines @@
     visitor->trace(m_responseDocumentParser);
     visitor->trace(m_progressEventThrottle);
     visitor->trace(m_upload);
     visitor->trace(m_blobLoader);
     XMLHttpRequestEventTarget::trace(visitor);
     DocumentParserClient::trace(visitor);
     ActiveDOMObject::trace(visitor);
 }
 
 } // namespace blink