[css-syntax] Add issue about charset propagating across origin boundaries.

Author: tabatkins

css-syntax/Overview.html

@@ -631,6 +631,9 @@ <h3 id=the-input-byte-stream><span class=secno>3.2. </span> The input byte
    algorithm as a whole cleaner. Perhaps abstract it into the concept of an
    "environment charset" or something?
 
+  <p class=issue> Should we only take the charset from the referring document
+   if it's same-origin?
+
   <h4 id=preprocessing-the-input-stream><span class=secno>3.2.1. </span>
    Preprocessing the input stream</h4>
 

css-syntax/Overview.src.html

@@ -369,6 +369,9 @@ <h3>
 		to make the algorithm as a whole cleaner.
 		Perhaps abstract it into the concept of an "environment charset" or something?
 
+	<p class='issue'>
+		Should we only take the charset from the referring document if it's same-origin?
+
 
 <h4>
 Preprocessing the input stream</h4>