Lower priority of async scripts

Source/core/html/parser/HTMLResourcePreloader.cpp

 /*
  * Copyright (C) 2013 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 70 matching lines @@
     PreloadRequestStream requests;
     requests.swap(r);
 
     for (PreloadRequestStream::iterator it = requests.begin(); it != requests.end(); ++it)
         preload(it->release());
 }
 
 void HTMLResourcePreloader::preload(PassOwnPtr<PreloadRequest> preload)
 {
     FetchRequest request = preload->resourceRequest(m_document);
+    request.setExecAsync(preload->execAsync());
     blink::Platform::current()->histogramCustomCounts("WebCore.PreloadDelayMs", static_cast<int>(1000 * (monotonicallyIncreasingTime() - preload->discoveryTime())), 0, 2000, 20);
     m_document->fetcher()->preload(preload->resourceType(), request, preload->charset());
 }
 
 }