[cssom] Use default value in IDL for CSSStyleDeclaration#setProperty's third argument. Also fix placement of [TreatNullAs=EmptyString]. http://www.w3.org/mid/4FA8AA5E.6020700@mit.edu

Author: Simon Pieters

cssom/Overview.html

@@ -2079,7 +2079,7 @@ <h4 id="the-cssstyledeclaration-interface"><span class="secno">6.5.1 </span>The
   getter DOMString <a href="#dom-cssstyledeclaration-item" title="dom-CSSStyleDeclaration-item">item</a>(unsigned long index);
   DOMString <a href="#dom-cssstyledeclaration-getpropertyvalue" title="dom-CSSStyleDeclaration-getPropertyValue">getPropertyValue</a>(DOMString property);
   DOMString <a href="#dom-cssstyledeclaration-getpropertypriority" title="dom-CSSStyleDeclaration-getPropertyPriority">getPropertyPriority</a>(DOMString property);
-  void <a href="#dom-cssstyledeclaration-setproperty" title="dom-CSSStyleDeclaration-setProperty">setProperty</a>(DOMString property, DOMString value, optional [TreatNullAs=EmptyString] DOMString priority);
+  void <a href="#dom-cssstyledeclaration-setproperty" title="dom-CSSStyleDeclaration-setProperty">setProperty</a>(DOMString property, DOMString value, [TreatNullAs=EmptyString] optional DOMString priority = "");
   DOMString <a href="#dom-cssstyledeclaration-removeproperty" title="dom-CSSStyleDeclaration-removeProperty">removeProperty</a>(DOMString property);
   readonly attribute <a href="#cssrule">CSSRule</a>? <a href="#dom-cssstyledeclaration-length" title="dom-CSSStyleDeclaration-length">parentRule</a>;
 };</pre>
@@ -2147,7 +2147,6 @@ <h4 id="the-cssstyledeclaration-interface"><span class="secno">6.5.1 </span>The
  terminate this algorithm.</li>
  <li><p>If <var>value</var> is the empty string, invoke <code title="dom-CSSStyleDeclaration-removeProperty"><a href="#dom-cssstyledeclaration-removeproperty">removeProperty()</a></code>
  with <var>property</var> as argument and terminate this algorithm.</li>
- <li><p>If the <var>priority</var> argument has been omitted let <var>priority</var> be the empty string.</li>
  <li><p>If <var>priority</var> is neither a valid priority nor the empty string terminate this algorithm.</li>
  <li>
  <p>If <a href="#parse-a-css-value" title="parse a CSS value">parsing the <var>value</var></a> returns <code>null</code> terminate this algorithm.

cssom/Overview.src.html

@@ -2009,7 +2009,7 @@ <h4>The <code title>CSSStyleDeclaration</code> Interface</h4>
   getter DOMString <span title=dom-CSSStyleDeclaration-item>item</span>(unsigned long index);
   DOMString <span title=dom-CSSStyleDeclaration-getPropertyValue>getPropertyValue</span>(DOMString property);
   DOMString <span title=dom-CSSStyleDeclaration-getPropertyPriority>getPropertyPriority</span>(DOMString property);
-  void <span title=dom-CSSStyleDeclaration-setProperty>setProperty</span>(DOMString property, DOMString value, optional [TreatNullAs=EmptyString] DOMString priority);
+  void <span title=dom-CSSStyleDeclaration-setProperty>setProperty</span>(DOMString property, DOMString value, [TreatNullAs=EmptyString] optional DOMString priority = "");
   DOMString <span title=dom-CSSStyleDeclaration-removeProperty>removeProperty</span>(DOMString property);
   readonly attribute <span>CSSRule</span>? <span title=dom-CSSStyleDeclaration-length>parentRule</span>;
 };</pre>
@@ -2077,7 +2077,6 @@ <h4>The <code title>CSSStyleDeclaration</code> Interface</h4>
  terminate this algorithm.</p></li>
  <li><p>If <var>value</var> is the empty string, invoke <code title='dom-CSSStyleDeclaration-removeProperty'>removeProperty()</code>
  with <var>property</var> as argument and terminate this algorithm.</p></li>
- <li><p>If the <var>priority</var> argument has been omitted let <var>priority</var> be the empty string.</p></li>
  <li><p>If <var>priority</var> is neither a valid priority nor the empty string terminate this algorithm.</p></li>
  <li>
  <p>If <span title='parse a CSS value'>parsing the <var>value</var></span> returns <code>null</code> terminate this algorithm.