Revert "[css-anchor-position-1] Specify scroll offset snapshot timing #10796" (#13849)

This reverts commit 54fd028.

Author: tabatkins

css-anchor-position-1/Overview.bs

@@ -1075,9 +1075,6 @@ while still allowing as much freedom to anchor to various elements as possible,
 [=anchor positioning=] uses a combination of [=remembered scroll offsets=]
 and [=compensating for scroll=].
 
-The scroll offsets which are used to compute [=remembered scroll offsets=] and [=default scroll shift=] 
-are snapshotted when asked to [=run snapshot post-layout state steps=].
-
 <div class=note>
 	The details here are technical, but the gist is:
 
@@ -1239,6 +1236,10 @@ specifically, the [=default anchor element=]:
 	as if affected by a [=transform=]
 	(before any other transforms).
 
+	Issue: Define the precise timing of the snapshot:
+	updated each frame,
+	before style recalc.
+
 	Issue: Similar to [=remembered scroll offset=],
 	can we pay attention to transforms on the [=default anchor element=]?