Add CORS support for <link> elements.

Source/core/html/HTMLLinkElement.cpp

Index: Source/core/html/HTMLLinkElement.cpp
diff --git a/Source/core/html/HTMLLinkElement.cpp b/Source/core/html/HTMLLinkElement.cpp
index cc886008ace6cc162c2b06b48339ae03b32eacf9..52fd4033cc62dcb8451266986bbe8b524941d666 100644
--- a/Source/core/html/HTMLLinkElement.cpp
+++ b/Source/core/html/HTMLLinkElement.cpp
@@ -138,6 +138,11 @@ bool HTMLLinkElement::shouldLoadLink()
     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;
@@ -590,6 +595,11 @@ void LinkStyle::process()
 
         // 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()) {