[css-font-loading] Be more careful about setting FontFace user-visible state in a task, rather than just 'asynchronously'.

Author: tabatkins

css-font-loading/Overview.bs

@@ -176,7 +176,7 @@ The Constructor</h3>
 			according to the grammars of the corresponding descriptors of the CSS ''@font-face'' rule.
 			If any of them fail to parse correctly,
 			reject <var>font face's</var> <a>[<!---->[FontStatusPromise]]</a> with a DOMException named "SyntaxError" and abort these steps.
-			Otherwise, set <var>font face's</var> corresponding attributes to the serialization of the parsed values.
+			Otherwise, queue a task to set <var>font face's</var> corresponding attributes to the serialization of the parsed values.
 
 		<li>
 			If the <a>source</a> argument was a <a>DOMString</a>,
@@ -199,8 +199,8 @@ The Constructor</h3>
 
 		<li>
 			If <var>font face's</var> <a>[<!---->[Data]]</a> slot is not <code>null</code>,
-			set <var>font face's</var> <a for=FontFace>status</a> attribute to "loading",
-			and attempt to parse the data in it as a font.
+			queue a task to set <var>font face's</var> <a for=FontFace>status</a> attribute to "loading".
+			Attempt to parse the data in it as a font.
 			When this is completed,
 			successfully or not,
 			await a stable state,

css-font-loading/Overview.html

@@ -292,7 +292,7 @@ <h3 class="heading settled heading" data-level=2.1 id=font-face-constructor><spa
 			according to the grammars of the corresponding descriptors of the CSS <a class=css data-link-type=maybe href=http://dev.w3.org/csswg/css-fonts-3/#at-font-face-rule title=@font-face>@font-face</a> rule.
 			If any of them fail to parse correctly,
 			reject <var>font face’s</var> <a data-link-type=idl href=#dom-fontface-fontstatuspromise title=[[fontstatuspromise]]>[[FontStatusPromise]]</a> with a DOMException named "SyntaxError" and abort these steps.
-			Otherwise, set <var>font face’s</var> corresponding attributes to the serialization of the parsed values.
+			Otherwise, queue a task to set <var>font face’s</var> corresponding attributes to the serialization of the parsed values.
 
 		<li>
 			If the <a data-link-type=idl href=#dom-fontfacefontface-source title=source>source</a> argument was a <a data-link-type=idl title=domstring>DOMString</a>,
@@ -315,8 +315,8 @@ <h3 class="heading settled heading" data-level=2.1 id=font-face-constructor><spa
 
 		<li>
 			If <var>font face’s</var> <a data-link-type=idl href=#dom-fontface-data title=[[data]]>[[Data]]</a> slot is not <code>null</code>,
-			set <var>font face’s</var> <a data-link-for=FontFace data-link-type=idl href=#dom-fontface-status title=status>status</a> attribute to "loading",
-			and attempt to parse the data in it as a font.
+			queue a task to set <var>font face’s</var> <a data-link-for=FontFace data-link-type=idl href=#dom-fontface-status title=status>status</a> attribute to "loading".
+			Attempt to parse the data in it as a font.
 			When this is completed,
 			successfully or not,
 			await a stable state,