exclude no-cors cross-origin stylesheet subresources

closes #27

index.html

@@ -690,7 +690,12 @@ <h3>Processing Model</h3>
   <li>Set the <i>primary buffer</i> to a size of 150, unless otherwise specified
   by the user agent or set by the <a href="#widl-Performance-setResourceTimingBufferSize-void-unsigned-long-maxSize"><code>setResourceTimingBufferSize</code></a> method.
   </li>
-  <li>For each resource <a title='fetch' href="http://www.w3.org/TR/html5/infrastructure.html#fetch">fetched</a> by the current <a href="http://www.w3.org/TR/html5/browsers.html#browsing-context">browsing context</a>, perform the following steps:
+  <li>For each resource <a title='fetch' href="http://www.w3.org/TR/html5/infrastructure.html#fetch">fetched</a> by the current <a href="http://www.w3.org/TR/html5/browsers.html#browsing-context">browsing context</a>, excluding resources fetched by cross-origin stylesheets fetched with <code>no-cors</code> policy, perform the following steps:
+
+  <p class="issue">
+    Above cross-origin exclusion should be defined via Fetch registry: CSS needs to be defined in terms of Fetch and set some kind of "opaque request flag" for no-CORS CSS subresources. In turn, Resource Timing should interface with Fetch registry to surface resource fetch events.
+  </p>
+
   <ol>
       <li id="step-create-object">Create a new <a href="#performanceresourcetiming">PerformanceResourceTiming</a> object and
       set <a href="#entryType-attribute">entryType</a> to the DOMString <code>resource</code>.