Editorial: use associated Document in place of responsible document (#…

…579)

index.bs

@@ -2200,11 +2200,12 @@ aborted.
 
 <div algorithm="handle visibility change">
 When the user agent determines that the [=document visibility state|visibility
-state=] of the [=responsible document=] of the [=current settings object=]
-changes, it must run these steps:
+state=] of the <a>associated <code>Document</code></a> of the
+[=current settings object=]'s [=relevant global object=] changes, it must run
+these steps:
 
-1. Let <code>|document|</code> be the [=responsible document=] of the [=current
-    settings object=].
+1. Let <code>|document|</code> be the <a>associated <code>Document</code></a> of
+    the [=current settings object=]'s [=relevant global object=].
 1. If <code>|document|</code>'s [=document visibility state|visibility state=]
     is not <code>"visible"</code>, then [=abort all active watchAdvertisements=]
     operations.
@@ -2220,8 +2221,9 @@ active=] [=document=]. When [=fully active|full activity=] is lost, scanning
 operations for that [=document=] need to be aborted.
 
 <div algorithm="handle full activity loss">
-When the user agent determines that a [=responsible document=] of the [=current
-settings object=] is no longer [=fully active=], it must run these steps:
+When the user agent determines that a <a>associated <code>Document</code></a> of
+the [=current settings object=]'s [=relevant global object=] is no longer
+[=fully active=], it must run these steps:
 
 1. Run [=abort all active watchAdvertisements=] operations.