[css-transitions] Fix IDL syntax error found by http://www.w3.org/2009/07/webidl-check .

Author: dbaron

css-transitions/Overview.html

@@ -1252,7 +1252,7 @@ <h2 id=transition-events><span class=secno>5. </span><a
         href="#Events-TransitionEvent-elapsedTime">elapsedTime</a> = 0.0;
     DOMString <a
         href="#Events-TransitionEvent-pseudoElement">pseudoElement</a> = "";
-  }
+  };
   </pre>
       </div>
 

css-transitions/Overview.src.html

@@ -1295,7 +1295,7 @@ <h2 id="transition-events"><a title="" id="transition-events-">
     DOMString <a href="#Events-TransitionEvent-propertyName">propertyName</a> = "";
     float <a href="#Events-TransitionEvent-elapsedTime">elapsedTime</a> = 0.0;
     DOMString <a href="#Events-TransitionEvent-pseudoElement">pseudoElement</a> = "";
-  }
+  };
   </pre>
               </div>
             </dd>