Make sure getAttribute() / setAttribute() callers use AtomicStrings

Source/core/loader/ImageLoader.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2009, 2010 Apple Inc. All rights reserved.
  *
  * 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
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 139 matching lines @@
 
     if (!m_failedLoadURL.isEmpty() && attr == m_failedLoadURL)
         return;
 
     // Do not load any image if the 'src' attribute is missing or if it is
     // an empty string.
     ResourcePtr<ImageResource> newImage = 0;
     if (!attr.isNull() && !stripLeadingAndTrailingHTMLSpaces(attr).isEmpty()) {
         FetchRequest request(ResourceRequest(document.completeURL(sourceURI(attr))), element()->localName());
 
-        String crossOriginMode = m_element->fastGetAttribute(HTMLNames::crossoriginAttr);
+        AtomicString crossOriginMode = m_element->fastGetAttribute(HTMLNames::crossoriginAttr);
         if (!crossOriginMode.isNull()) {
             StoredCredentials allowCredentials = equalIgnoringCase(crossOriginMode, "use-credentials") ? AllowStoredCredentials : DoNotAllowStoredCredentials;
             updateRequestForAccessControl(request.mutableResourceRequest(), document.securityOrigin(), allowCredentials);
         }
 
         if (m_loadManually) {
             bool autoLoadOtherImages = document.fetcher()->autoLoadImages();
             document.fetcher()->setAutoLoadImages(false);
             newImage = new ImageResource(request.resourceRequest());
             newImage->setLoading(true);
@@ skipping 304 matching lines @@
         handle->notifyImageSourceChanged();
     }
 }
 
 inline void ImageLoader::clearFailedLoadURL()
 {
     m_failedLoadURL = AtomicString();
 }
 
 }