[css-view-transitions-1] Swap the order between setting the phase and calling the update callback (w3c#10826)

* [css-view-transitions-1] Swap the order between setting the phase and calling the update callback.

This fixes an issue where skipping the transition from within
thet update callback would call the update callback twice.

Closes w3c#10822

* Change order around

* Change order around

Author: noamr

css-view-transitions-1/Overview.bs

@@ -1598,6 +1598,8 @@ urlPrefix: https://wicg.github.io/navigation-api/; type: interface;
 
 		1. [=Assert=]: |transition|'s [=ViewTransition/phase=] is "`done`", or before "`update-callback-called`".
 
+		1. If |transition|'s [=ViewTransition/phase=] is not "`done`", then set |transition|'s [=ViewTransition/phase=] to "`update-callback-called`".
+
 		1. Let |callbackPromise| be null.
 
 		1. If |transition|'s [=ViewTransition/update callback=] is null,
@@ -1606,8 +1608,6 @@ urlPrefix: https://wicg.github.io/navigation-api/; type: interface;
 
 		1. Otherwise, set |callbackPromise| to the result of [=/invoking=] |transition|'s [=ViewTransition/update callback=].
 
-		1. If |transition|'s [=ViewTransition/phase=] is not "`done`", then set |transition|'s [=ViewTransition/phase=] to "`update-callback-called`".
-
 		1. Let |fulfillSteps| be to following steps:
 			1. [=Resolve=] |transition|'s [=ViewTransition/update callback done promise=] with undefined.
 
@@ -1986,6 +1986,7 @@ Changes from <a href="https://www.w3.org/TR/2023/WD-css-view-transitions-1-20230
 * Scope view transition names to matching tree context. See <a href="https://github.com/w3c/csswg-drafts/issues/10145">issue 10145</a>.
 * Fix scoping to match name instead of element. See <a href="https://github.com/w3c/csswg-drafts/issues/10145">issue 10145</a>.
 * Add a rendering characteristics note about out-of-viewport elements. See <a href="https://github.com/w3c/csswg-drafts/issues/8282">issue 8282</a>.
+* Swap the order of invoking the update callback and setting the phase. See <a href="https://github.com/w3c/csswg-drafts/issues/10822">issue 10822</a>.
 
 <h3 id="changes-since-2022-05-25">
 Changes from <a href="https://www.w3.org/TR/2023/WD-css-view-transitions-1-20230525/">2022-05-25 Working Draft</a>