Describe getComputedStyle() behavior of transform in terms of resolved value.

This describes the special getComputedStyle() behavior for the transform
property by using the correct hook provided by the cssom, which is the
term "resolved value special case property".

Fixes #4869

Author: dbaron

css-transforms-1/Overview.bs

@@ -390,17 +390,23 @@ Serialization of <<transform-function>>s {#serialization-of-transform-functions}
 
 To serialize the <<transform-function>>s, serialize as per their individual grammars, in the order the grammars are written in, avoiding <<calc()>> expressions where possible, avoiding <<calc()>> transformations, omitting components when possible without changing the meaning, joining space-separated tokens with a single space, and following each serialized comma with a single space.
 
-Serialization of the computed value of <<transform-list>> {#serialization-of-the-computed-value}
+Resolved value of 'transform' {#serialization-of-the-computed-value}
 ----------------------------------------------------------------
 
-A <<transform-list>> for the computed value is serialized to one <<matrix()>> function by the following algorithm:
+The 'transform' property is a <a>resolved value special case property</a>. [[!CSSOM]]
+
+When the <a>computed value</a> is a <<transform-list>>,
+the <a>resolved value</a> is one <<matrix()>> function
+computed by the following algorithm:
 
 <ol class="algorithm">
-	1. Let <var>transform</var> be a 4x4 matrix initialized to the identity matrix. The elements <var ignore> m11</var>, <var ignore>m22</var>, <var ignore>m33</var> and <var ignore>m44</var> of <var>transform</var> must be set to ''1'' all other elements of <var>transform</var> must be set to ''0''.
+	1. Let <var>transform</var> be a 4x4 matrix initialized to the identity matrix. The elements <var ignore>m11</var>, <var ignore>m22</var>, <var ignore>m33</var> and <var ignore>m44</var> of <var>transform</var> must be set to ''1''; all other elements of <var>transform</var> must be set to ''0''.
 	2. Post-multiply all <<transform-function>>s in <<transform-list>> to <var>transform</var>.
 	3. Serialize <var>transform</var> to a <<matrix()>> function.
 </ol>
 
+For other computed values, the <a>resolved value</a> is the <a>computed value</a>.
+
 The 'transform-origin' Property {#transform-origin-property}
 ============================================================
 

css-transforms-2/Overview.bs

@@ -136,13 +136,17 @@ Terminology {#terminology}
 :: A set of elements with a common ancestor which share a common three-dimensional coordinate system, as described <a href="#3d-rendering-contexts">below</a>.
 
 
-Serialization of the <a>computed value</a> of <<transform-list>> {#serialization-of-the-computed-value}
+Resolved value of 'transform' {#serialization-of-the-computed-value}
 ----------------------------------------------------------------
 
-A <<transform-list>> for the <a>computed value</a> is serialized to either one <<matrix()>> or one <<matrix3d()>> function by the following algorithm:
+The 'transform' property is a <a>resolved value special case property</a>. [[!CSSOM]]
+
+When the <a>computed value</a> is a <<transform-list>>,
+the <a>resolved value</a> is one <<matrix()>> function or one <<matrix3d()>> function
+computed by the following algorithm:
 
 <ol class="algorithm">
-	1. Let <var>transform</var> be a 4x4 matrix initialized to the identity matrix. The elements <var ignore> m11</var>, <var ignore>m22</var>, <var ignore>m33</var> and <var ignore>m44</var> of <var>transform</var> must be set to ''1'' all other elements of <var>transform</var> must be set to ''0''.
+	1. Let <var>transform</var> be a 4x4 matrix initialized to the identity matrix. The elements <var ignore>m11</var>, <var ignore>m22</var>, <var ignore>m33</var> and <var ignore>m44</var> of <var>transform</var> must be set to ''1''; all other elements of <var>transform</var> must be set to ''0''.
 	2. Post-multiply all <<transform-function>>s in <<transform-list>> to <var>transform</var>.
 	3. Chose between <<matrix()>> or <<matrix3d()>> serialization:
 		<dl class="switch">
@@ -153,7 +157,7 @@ A <<transform-list>> for the <a>computed value</a> is serialized to either one <
 		</dl>
 </ol>
 
-Issue: fix this text to add to the text in CSS Transforms 1.
+For other computed values, the <a>resolved value</a> is the <a>computed value</a>.
 
 Two Dimensional Subset {#two-dimensional-subset}
 ================================================