Editorial: remove a reference to "responsible document"

Part of whatwg/html#4335.

Author: domenic

fetch.bs

@@ -1449,8 +1449,8 @@ not always relevant and might require different behavior.
  submission algorithm.
 
  <p>CSP will also need to check <a for=/>request</a>'s <a for=request>client</a>'s
- <a for="environment settings object">responsible document</a>'s
- <a for=Document>browsing context</a>'s <a>ancestor browsing contexts</a> for various CSP
+ <a for="environment settings object">global object</a>'s
+ <a for=Window>browsing context</a>'s <a>ancestor browsing contexts</a> for various CSP
  directives.
 </div>