[css-contain-2] Try to fix the prose for initial determination to happen sync, effectively.

Author: emilio

css-contain-2/Overview.bs

@@ -1999,15 +1999,13 @@ Suppressing An Element's Contents Entirely: the 'content-visibility' property {#
 	</div>
 
 	<div algorithm="update content relevancy for a document">
-		To <dfn export>update content relevancy for a document</dfn> given a document <var>doc</var>, and a boolean <var>isFirstIteration</var>:
+		To <dfn export>update content relevancy for a document</dfn> given a document <var>doc</var>, and a boolean <var>updateNonInitial</var>:
 
 		1. Let <var>changed</var> be false.
 		1. For each <var>element</var> [=connected=] to doc with ''auto'' used value of ''content-visibility''
-			1. Determine proximity to the viewport for <var>element</var>.
-			1. If <var>element</var> is not [=currently relevant to the user=] and <var>element</var> is [=relevant to the user=], then:
-				2. Set <var>changed</var> to true.
-				2. Set <var>element</var>'s [=currently relevant to the user=] flag to true.
-			1. If <var>isFirstIteration</var> is false, then [=continue=].
+			1. Let <var>isInitialDetermination</var> be true if <var>element</var>'s [=proximity to the viewport=] is [=not determined=], otherwise false.
+			1. Determine [=proximity to the viewport=] for <var>element</var>.
+			1. If <var>updateNonInitial</var> is false and <var>isInitialDetermination</var> is false, then [=continue=].
 			1. If <var>element</var> is [=relevant to the user=], then:
 				1. If <var>element</var>'s [=currently relevant to the user=] flag is false, set <var>changed</var> to true.
 				1. Set <var>element</var>'s [=currently relevant to the user=] flag to true.
@@ -2017,10 +2015,12 @@ Suppressing An Element's Contents Entirely: the 'content-visibility' property {#
 		1. return <var>changed</var>.
 
 		<div class=note>
-		The intent of the <var>changed</var> variable is for the initial viewport
-		proximity determination, which takes effect immediately, to be reflected in
-		the style and layout calculation which is carried out in a previous step of
-		this loop. Proximity determinations other than the initial one take effect
+		The intent of the <var>changed</var> and <var>updateNonInitial</var>
+		variables is for the initial viewport proximity determination, which takes
+		effect immediately, to be reflected in the style and layout calculation
+		this frame.
+
+		Proximity determinations other than the initial one take effect
 		at the next rendering opportunity.
 		</div>
 	</div>