Add pointerevent's attributes

Author: LanWei22

index.html

@@ -7814,6 +7814,17 @@ <h3>Processing actions</h3>
  <li><p>Set the <code>button</code> property of <var>action</var>
   to <var>button</var>.
 
+<li><p>Let <var>width</var> be the result
+  of getting the property <code>width</code>
+  from <var>action item</var>.
+
+ <li><p>If <var>width</var> is not a <a>Number</a> greater than or
+  equal to 0 return <a>error</a> with <a>error code</a>
+  <a>invalid argument</a>.
+
+ <li><p>Set the <code>width</code> property of <var>action</var>
+  to <var>width</var>.
+
  <li><p>Return success with data <a><code>null</code></a>.
 </ol>