[cssom] Make 'parse a CSS value' work for case-sensitive properties

Author: Simon Pieters

cssom/Overview.html

@@ -2119,9 +2119,11 @@ <h4 id="parsing-css-values"><span class="secno">6.6.1 </span>Parsing CSS Values<
   <var>property</var> means to a parse the given value according to
   the definition of the property that is an
   <a class="external" href="http://dom.spec.whatwg.org/#ascii-case-insensitive">ASCII case-insensitive</a> match for
-  <var>property</var> in the CSS specification. If the given value
-  is <span>ignored</span> return <code>null</code>. Otherwise return the CSS value for
-  the given <var>property</var>.</p>
+  <var>property</var> in the CSS specification, if <var>property</var> is defined to be
+  case-insensitive, or otherwise that is a
+  <a class="external" href="http://dom.spec.whatwg.org/#case-sensitive">case-sensitive</a> match for <var>property</var> in the
+  CSS specification. If the given value is <span>ignored</span> return <code>null</code>.
+  Otherwise return the CSS value for the given <var>property</var>.</p>
 
   <p class="note">"<code>!important</code>" declarations are not
   part of the property value space and will therefore cause

cssom/cssom-source

@@ -1675,9 +1675,11 @@
   <var>property</var> means to a parse the given value according to
   the definition of the property that is an
   <span data-anolis-spec=dom>ASCII case-insensitive</span> match for
-  <var>property</var> in the CSS specification. If the given value
-  is <span>ignored</span> return <code>null</code>. Otherwise return the CSS value for
-  the given <var>property</var>.</p>
+  <var>property</var> in the CSS specification, if <var>property</var> is defined to be
+  case-insensitive, or otherwise that is a
+  <span data-anolis-spec=dom>case-sensitive</span> match for <var>property</var> in the
+  CSS specification. If the given value is <span>ignored</span> return <code>null</code>.
+  Otherwise return the CSS value for the given <var>property</var>.</p>
 
   <p class="note">"<code>!important</code>" declarations are not
   part of the property value space and will therefore cause