Fix double resource request for script resources with integrity attr.

third_party/WebKit/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 283 matching lines @@
         if (crossOrigin != CrossOriginAttributeNotSet)
             request.setCrossOriginAccessControl(elementDocument->securityOrigin(), crossOrigin);
         request.setCharset(scriptCharset());
 
         bool scriptPassesCSP = elementDocument->contentSecurityPolicy()->allowScriptWithNonce(m_element->fastGetAttribute(HTMLNames::nonceAttr));
         if (scriptPassesCSP)
             request.setContentSecurityCheck(DoNotCheckContentSecurityPolicy);
         request.setDefer(defer);
 
         String integrityAttr = m_element->fastGetAttribute(HTMLNames::integrityAttr);
         IntegrityMetadataSet metadataSet;

[sof, 2016/01/06 07:38:13]

Looks like you can push this local variable into the "if" below.

[jww, 2016/01/06 18:37:53]

Done.

         if (!integrityAttr.isEmpty()) {
             SubresourceIntegrity::parseIntegrityAttribute(integrityAttr, metadataSet, elementDocument.get());
             request.setIntegrityMetadata(metadataSet);
         }
 
         m_resource = ScriptResource::fetch(request, elementDocument->fetcher());
-        if (m_resource && !integrityAttr.isEmpty())
-            m_resource->setIntegrityMetadata(metadataSet);
 
         m_isExternalScript = true;
     }
 
     if (m_resource)
         return true;
 
     dispatchErrorEvent();
     return false;
 }
@@ skipping 192 matching lines @@
     if (isHTMLScriptLoader(element))
         return toHTMLScriptElement(element)->loader();
 
     if (isSVGScriptLoader(element))
         return toSVGScriptElement(element)->loader();
 
     return 0;
 }
 
 } // namespace blink