Always report access control failure if accessing unsupported URL.

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 93 matching lines @@
         return;
     }
 
     makeCrossOriginAccessRequest(request);
 }
 
 void DocumentThreadableLoader::makeCrossOriginAccessRequest(const ResourceRequest& request)
 {
     ASSERT(m_options.crossOriginRequestPolicy == UseAccessControl);
 
+    // Cross-origin requests are only allowed certain registered schemes.
+    // We would catch this when checking response headers later, but there
+    // is no reason to send a request, preflighted or not, that's guaranteed
+    // to be denied.
+    if (!SchemeRegistry::shouldTreatURLSchemeAsCORSEnabled(request.url().protocol())) {
+        m_client->didFailAccessControlCheck(ResourceError(errorDomainBlinkInternal, 0, request.url().string(), "Cross origin requests are only supported for protocol schemes: " + SchemeRegistry::listOfCORSEnabledURLSchemes() + "."));
+        return;
+    }
+
     if ((m_options.preflightPolicy == ConsiderPreflight && isSimpleCrossOriginAccessRequest(request.httpMethod(), request.httpHeaderFields())) || m_options.preflightPolicy == PreventPreflight) {
-        // Cross-origin requests are only allowed for HTTP and registered schemes. We would catch this when checking response headers later, but there is no reason to send a request that's guaranteed to be denied.
-        if (!SchemeRegistry::shouldTreatURLSchemeAsCORSEnabled(request.url().protocol())) {
-            m_client->didFailAccessControlCheck(ResourceError(errorDomainBlinkInternal, 0, request.url().string(), "Cross origin requests are only supported for HTTP."));
-            return;
-        }
-
         ResourceRequest crossOriginRequest(request);
         ResourceLoaderOptions crossOriginOptions(m_resourceLoaderOptions);
         updateRequestForAccessControl(crossOriginRequest, securityOrigin(), effectiveAllowCredentials());
         loadRequest(crossOriginRequest, crossOriginOptions);
     } else {
         m_simpleRequest = false;
 
         OwnPtr<ResourceRequest> crossOriginRequest = adoptPtr(new ResourceRequest(request));
         OwnPtr<ResourceLoaderOptions> crossOriginOptions = adoptPtr(new ResourceLoaderOptions(m_resourceLoaderOptions));
         // Do not set the Origin header for preflight requests.
@@ skipping 365 matching lines @@
         return DoNotAllowStoredCredentials;
     return m_resourceLoaderOptions.allowCredentials;
 }
 
 SecurityOrigin* DocumentThreadableLoader::securityOrigin() const
 {
     return m_securityOrigin ? m_securityOrigin.get() : m_document.securityOrigin();
 }
 
 } // namespace WebCore