Add CORS support for <link> elements.

Source/core/html/HTMLLinkElement.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, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Rob Buis (rwlbuis@gmail.com)
  * Copyright (C) 2011 Google 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
@@ skipping 120 matching lines @@
     // let the latest (innermost) mutation occur.
     if (recursionRank != m_beforeLoadRecurseCount)
         continueLoad = false;
 
     if (recursionRank == 1)
         m_beforeLoadRecurseCount = 0;
 
     return continueLoad;
 }
 
+bool HTMLLinkElement::loadLink(const String& type, const KURL& url)
+{
+    return m_linkLoader.loadLink(m_relAttribute, fastGetAttribute(HTMLNames::crossoriginAttr), type, url, document());
+}
+
 LinkResource* HTMLLinkElement::linkResourceToProcess()
 {
     bool visible = inDocument() && !m_isInShadowTree;
     if (!visible) {
         ASSERT(!linkStyle() || !linkStyle()->hasSheet());
         return 0;
     }
 
     if (!m_link) {
         if (m_relAttribute.isImport() && RuntimeEnabledFeatures::htmlImportsEnabled())
@@ skipping 432 matching lines @@
             mediaQueryMatches = evaluator.eval(media.get());
         }
 
         // Don't hold up render tree construction and script execution on stylesheets
         // that are not needed for the rendering at the moment.
         bool blocking = mediaQueryMatches && !m_owner->isAlternate();
         addPendingSheet(blocking ? Blocking : NonBlocking);
 
         // Load stylesheets that are not needed for the rendering immediately with low priority.
         FetchRequest request = builder.build(blocking);
+        AtomicString crossOriginMode = m_owner->fastGetAttribute(HTMLNames::crossoriginAttr);
+        if (!crossOriginMode.isNull()) {
+            StoredCredentials allowCredentials = equalIgnoringCase(crossOriginMode, "use-credentials") ? AllowStoredCredentials : DoNotAllowStoredCredentials;

[abarth-chromium, 2014/01/28 06:38:45]

Should we make a helper function that does this work?  I feel like we have this
same line of code copy/pasted in a bunch of places.

[sof, 2014/01/28 07:23:01]

Great suggestion, less repetition.

Added FetchRequest::setCrossOriginAccessControl(securityOrigin, crossOriginMode)
(and used it without abandon.)

+            request.setCrossOriginAccessControl(document().securityOrigin(), allowCredentials);
+        }
         setResource(document().fetcher()->fetchCSSStyleSheet(request));
 
         if (!resource()) {
             // The request may have been denied if (for example) the stylesheet is local and the document is remote.
             m_loading = false;
             removePendingSheet();
         }
     } else if (m_sheet) {
         // we no longer contain a stylesheet, e.g. perhaps rel or type was changed
         RefPtr<StyleSheet> removedSheet = m_sheet;
@@ skipping 11 matching lines @@
 void LinkStyle::ownerRemoved()
 {
     if (m_sheet)
         clearSheet();
 
     if (styleSheetIsLoading())
         removePendingSheet(RemovePendingSheetNotifyLater);
 }
 
 } // namespace WebCore