Convert svg repaint tests to pixel test only repaint

LayoutTests/svg/custom/prevent-default.svg

-<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" onload="runRepaintTest()">
-  <script xlink:href="../../fast/repaint/resources/repaint.js"/>
+<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" onload="runRepaintAndPixelTest()">
+  <script xlink:href="../../fast/repaint/resources/text-based-repaint.js"/>
   <defs>
     <script type="text/ecmascript">
       <![CDATA[
         function changeColor(evt) {
           evt.target.setAttribute('fill', 'green'); 
           evt.stopPropagation();
           evt.preventDefault();
           if (window.testRunner)
             testRunner.notifyDone();
         }
         
         function repaintTest() {
           if (window.eventSender) {
             testRunner.waitUntilDone();
             eventSender.mouseMoveTo(50, 50);
             eventSender.mouseDown();
             eventSender.mouseUp();
           }
         }
       ]]>
     </script>
   </defs>
   <a xlink:href="javascript:void(document.getElementById('rect').style.fill='red')">
     <rect id='rect' onclick="changeColor(evt)" width='100' height='100' fill='orange' />
   </a>
 </svg>