[XHR] Tidy up files for testing XHR's error for mixed content check failure

Source/core/loader/DocumentThreadableLoader.cpp

 /*
  * Copyright (C) 2011, 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 575 matching lines @@
         if (m_actualRequest)
             resourceLoaderOptions.dataBufferingPolicy = BufferData;
 
         if (m_options.timeoutMilliseconds > 0)
             m_timeoutTimer.startOneShot(m_options.timeoutMilliseconds / 1000.0, FROM_HERE);
 
         FetchRequest newRequest(request, m_options.initiator, resourceLoaderOptions);
         if (m_options.crossOriginRequestPolicy == AllowCrossOriginRequests)
             newRequest.setOriginRestriction(FetchRequest::NoOriginRestriction);
         ASSERT(!resource());
+
         if (request.requestContext() == WebURLRequest::RequestContextVideo || request.requestContext() == WebURLRequest::RequestContextAudio)
             setResource(RawResource::fetchMedia(newRequest, m_document.fetcher()));
         else
             setResource(RawResource::fetch(newRequest, m_document.fetcher()));
-        if (resource() && resource()->loader()) {
+
+        if (!resource()) {
+            m_client->didFail(ResourceError(errorDomainBlinkInternal, 0, requestURL.string(), "Failed to start loading."));
+            return;
+        }
+
+        if (resource()->loader()) {
             unsigned long identifier = resource()->identifier();
             InspectorInstrumentation::documentThreadableLoaderStartedLoadingForClient(&m_document, identifier, m_client);
         }
         return;
     }
 
     FetchRequest fetchRequest(request, m_options.initiator, resourceLoaderOptions);
     if (m_options.crossOriginRequestPolicy == AllowCrossOriginRequests)
         fetchRequest.setOriginRestriction(FetchRequest::NoOriginRestriction);
     ResourcePtr<Resource> resource = RawResource::fetchSynchronously(fetchRequest, m_document.fetcher());
@@ skipping 53 matching lines @@
         return DoNotAllowStoredCredentials;
     return m_resourceLoaderOptions.allowCredentials;
 }
 
 SecurityOrigin* DocumentThreadableLoader::securityOrigin() const
 {
     return m_securityOrigin ? m_securityOrigin.get() : m_document.securityOrigin();
 }
 
 } // namespace blink