Replace several uses of toWebCoreString() by V8TRYCATCH_FOR_V8STRINGRESOURCE() macro

Source/bindings/v8/custom/V8XMLHttpRequestCustom.cpp

 /*
  * Copyright (C) 2008, 2009, 2010 Google Inc. All rights reserved.
  *
  * 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.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 154 matching lines @@
     // open(method, url, async, user)
     // open(method, url, async, user, passwd)
 
     if (args.Length() < 2) {
         throwNotEnoughArgumentsError(args.GetIsolate());
         return;
     }
 
     XMLHttpRequest* xmlHttpRequest = V8XMLHttpRequest::toNative(args.Holder());
 
-    String method = toWebCoreString(args[0]);
-    String urlstring = toWebCoreString(args[1]);
+    V8TRYCATCH_FOR_V8STRINGRESOURCE_VOID(V8StringResource<>, method, args[0]);
+    V8TRYCATCH_FOR_V8STRINGRESOURCE_VOID(V8StringResource<>, urlstring, args[1]);
 
     ScriptExecutionContext* context = getScriptExecutionContext();
     KURL url = context->completeURL(urlstring);
 
     ExceptionState es(args.GetIsolate());
 
     if (args.Length() >= 3) {
         bool async = args[2]->BooleanValue();
 
         if (args.Length() >= 4 && !args[3]->IsUndefined()) {
@@ skipping 61 matching lines @@
             ASSERT(arrayBufferView);
             xmlHttpRequest->send(arrayBufferView, es);
         } else
             xmlHttpRequest->send(toWebCoreStringWithNullCheck(arg), es);
     }
 
     es.throwIfNeeded();
 }
 
 } // namespace WebCore