[css-font-loading] Add support for the new terminology and alias the old (#14197)

Author: dcrescalante

css-font-loading-3/Overview.bs

@@ -85,7 +85,8 @@ The <code>FontFace</code> Interface</h2>
 		dictionary FontFaceDescriptors {
 			CSSOMString style = "normal";
 			CSSOMString weight = "normal";
-			CSSOMString stretch = "normal";
+			CSSOMString width;
+			CSSOMString stretch = "normal"; // alias for width, sets the same attribute
 			CSSOMString unicodeRange = "U+0-10FFFF";
 			CSSOMString featureSettings = "normal";
 			CSSOMString variationSettings = "normal";
@@ -99,25 +100,26 @@ The <code>FontFace</code> Interface</h2>
 
 		[Exposed=(Window,Worker)]
 		interface FontFace {
-			constructor(CSSOMString family, (CSSOMString or BufferSource) source,
-		                optional FontFaceDescriptors descriptors = {});
-			attribute CSSOMString family;
-			attribute CSSOMString style;
-			attribute CSSOMString weight;
-			attribute CSSOMString stretch;
-			attribute CSSOMString unicodeRange;
-			attribute CSSOMString featureSettings;
-			attribute CSSOMString variationSettings;
-			attribute CSSOMString display;
-			attribute CSSOMString ascentOverride;
-			attribute CSSOMString descentOverride;
-			attribute CSSOMString lineGapOverride;
-
-			readonly attribute FontFaceLoadStatus status;
-
-			Promise<FontFace> load();
-			readonly attribute Promise<FontFace> loaded;
-		};
+		  [Throws]
+		  constructor(CSSOMString family,
+		              (CSSOMString or BufferSource) source,
+		              optional FontFaceDescriptors descriptors = {});
+
+		  [SetterThrows] attribute CSSOMString family;
+		  [SetterThrows] attribute CSSOMString style;
+		  [SetterThrows] attribute CSSOMString weight;
+		  [SetterThrows, BindingAlias="stretch"] attribute CSSOMString width;
+		  [SetterThrows] attribute CSSOMString unicodeRange;
+		  [SetterThrows] attribute CSSOMString variant;
+		  [SetterThrows] attribute CSSOMString featureSettings;
+		  [SetterThrows, Pref="layout.css.font-variations.enabled"] attribute CSSOMString variationSettings;
+		  [SetterThrows] attribute CSSOMString display;
+		  [SetterThrows] attribute CSSOMString ascentOverride;
+		  [SetterThrows] attribute CSSOMString descentOverride;
+		  [SetterThrows] attribute CSSOMString lineGapOverride;
+		  [SetterThrows] attribute CSSOMString sizeAdjust;
+
+		  readonly attribute FontFaceLoadStatus status;
 	</xmp>
 
 	<wpt>
@@ -134,6 +136,7 @@ The <code>FontFace</code> Interface</h2>
 		: <dfn>family</dfn>
 		: <dfn>style</dfn>
 		: <dfn>weight</dfn>
+		: <dfn>width</dfn>
 		: <dfn>stretch</dfn>
 		: <dfn>unicodeRange</dfn>
 		::
@@ -154,6 +157,7 @@ The <code>FontFace</code> Interface</h2>
 			throw a {{SyntaxError}};
 			otherwise, set the attribute to the serialization of the parsed value.
 
+			Note that ''stretch'' is a legacy name alias of ''width'' and therefore they set the same attribute.
 		: <dfn>featureSettings</dfn>
 		: <dfn>variationSettings</dfn>
 		: <dfn>display</dfn>
@@ -416,7 +420,7 @@ Interaction with CSS’s ''@font-face'' Rule</h3>
 	This {{FontFace}} object is <dfn>CSS-connected</dfn>.
 
 	The {{FontFace}} object corresponding to a ''@font-face'' rule
-	has its {{FontFace/family}}, {{FontFace/style}}, {{FontFace/weight}}, {{FontFace/stretch}}, {{FontFace/unicodeRange}}, {{FontFace/variant}}, and {{FontFace/featureSettings}} attributes
+	has its {{FontFace/family}}, {{FontFace/style}}, {{FontFace/weight}}, {{FontFace/width}}, {{FontFace/unicodeRange}}, {{FontFace/variant}}, and {{FontFace/featureSettings}} attributes
 	set to the same value as the corresponding descriptors in the ''@font-face'' rule.
 	There is a two-way connection between the two:
 	any change made to a ''@font-face'' descriptor is immediately reflected in the corresponding {{FontFace}} attribute,