Lower priority of async scripts

Source/core/dom/ScriptLoader.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nikolas Zimmermann <zimmermann@kde.org>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 199 matching lines @@
 
     if (!isScriptForEventSupported())
         return false;
 
     if (!client->charsetAttributeValue().isEmpty())
         m_characterEncoding = client->charsetAttributeValue();
     else
         m_characterEncoding = elementDocument.charset();
 
     if (client->hasSourceAttribute()) {
-        if (!fetchScript(client->sourceAttributeValue()))
+        FetchRequest::DeferOption defer = FetchRequest::NoDefer;
+        if (!m_parserInserted || client->asyncAttributeValue() || client->deferAttributeValue())
+            defer = FetchRequest::LazyLoad;
+        if (!fetchScript(client->sourceAttributeValue(), defer))
             return false;
     }
 
     if (client->hasSourceAttribute() && client->deferAttributeValue() && m_parserInserted && !client->asyncAttributeValue()) {
         m_willExecuteWhenDocumentFinishedParsing = true;
         m_willBeParserExecuted = true;
     } else if (client->hasSourceAttribute() && m_parserInserted && !client->asyncAttributeValue()) {
         m_willBeParserExecuted = true;
     } else if (!client->hasSourceAttribute() && m_parserInserted && !elementDocument.isRenderingReady()) {
         m_willBeParserExecuted = true;
         m_readyToBeParserExecuted = true;
     } else if (client->hasSourceAttribute() && !client->asyncAttributeValue() && !m_forceAsync) {
         m_willExecuteInOrder = true;
         contextDocument->scriptRunner()->queueScriptForExecution(this, m_resource, ScriptRunner::IN_ORDER_EXECUTION);
         m_resource->addClient(this);
     } else if (client->hasSourceAttribute()) {
         contextDocument->scriptRunner()->queueScriptForExecution(this, m_resource, ScriptRunner::ASYNC_EXECUTION);
         m_resource->addClient(this);
     } else {
         // Reset line numbering for nested writes.
         TextPosition position = elementDocument.isInDocumentWrite() ? TextPosition() : scriptStartPosition;
         KURL scriptURL = (!elementDocument.isInDocumentWrite() && m_parserInserted) ? elementDocument.url() : KURL();
         executeScript(ScriptSourceCode(scriptContent(), scriptURL, position));
     }
 
     return true;
 }
 
-bool ScriptLoader::fetchScript(const String& sourceUrl)
+bool ScriptLoader::fetchScript(const String& sourceUrl, FetchRequest::DeferOption defer)
 {
     ASSERT(m_element);
 
     RefPtrWillBeRawPtr<Document> elementDocument(m_element->document());
     if (!m_element->inDocument() || m_element->document() != elementDocument)
         return false;
 
     ASSERT(!m_resource);
     if (!stripLeadingAndTrailingHTMLSpaces(sourceUrl).isEmpty()) {
         FetchRequest request(ResourceRequest(elementDocument->completeURL(sourceUrl)), m_element->localName());
 
         AtomicString crossOriginMode = m_element->fastGetAttribute(HTMLNames::crossoriginAttr);
         if (!crossOriginMode.isNull())
             request.setCrossOriginAccessControl(elementDocument->securityOrigin(), crossOriginMode);
         request.setCharset(scriptCharset());
 
         bool scriptPassesCSP = elementDocument->contentSecurityPolicy()->allowScriptWithNonce(m_element->fastGetAttribute(HTMLNames::nonceAttr));
         if (scriptPassesCSP)
             request.setContentSecurityCheck(DoNotCheckContentSecurityPolicy);
+        request.setDefer(defer);
 
         m_resource = elementDocument->fetcher()->fetchScript(request);
         m_isExternalScript = true;
     }
 
     if (m_resource)
         return true;
 
     dispatchErrorEvent();
     return false;
@@ skipping 163 matching lines @@
     if (isHTMLScriptLoader(element))
         return toHTMLScriptElement(element)->loader();
 
     if (isSVGScriptLoader(element))
         return toSVGScriptElement(element)->loader();
 
     return 0;
 }
 
 }