Unprefix usage of -webkit-transform in tests

LayoutTests/svg/custom/pointer-events-image-css-transform.svg

 <?xml version="1.0"?>
 <!-- This a 1-1 copy of pointer-events-image.svg tests with the addition of -webkit-transform -->
 <svg xmlns="http://www.w3.org/2000/svg"
      xmlns:xlink="http://www.w3.org/1999/xlink" onload="fillTestContent()">
   <script type="text/javascript">
   <![CDATA[
     
     if (window.testRunner)
         testRunner.waitUntilDone();
   
@@ skipping 37 matching lines @@
               var img = document.createElementNS(svgNS, 'image');
               img.setAttributeNS("http://www.w3.org/1999/xlink", 'href', 'resources/red-checker.png');
               img.setAttribute('x', xOffset/2);
               img.setAttribute('y', yOffset/2);
               img.setAttribute('width', 25);
               img.setAttribute('height', 25);
               img.setAttribute('visibility', visibleValues[vi]);
               img.setAttribute('fill', fillValues[fi]);
               img.setAttribute('stroke', strokeValues[si]);
               img.setAttribute('pointer-events', pointerEventsValues[pi]);
-              img.setAttribute('style', "-webkit-transform: scale(2)");
+              img.setAttribute('style', "transform: scale(2)");
               img.setAttribute('onclick', 'clickHit(evt, "' + identString + '")');
               
               testContent.appendChild(img);
             
               var fillText = document.createElementNS(svgNS, 'text');
               fillText.setAttribute('x', xOffset + 5);
               fillText.setAttribute('y', yOffset + 20);
               fillText.textContent = "miss";
               fillText.setAttribute('id', 'fill-text' + identString);
               fillText.setAttribute('pointer-events', 'none');
@@ skipping 16 matching lines @@
       if (window.testRunner)
         testRunner.notifyDone();
     }
   ]]>
   </script>
   
   <text x="110" y="20">Visibility: visible</text>
   <text x="340" y="20">Visibility: hidden</text>
   <g id="test-content"/>
 </svg>