Have SVGTextContentElement inherit SVGGraphicsElement

LayoutTests/svg/text/resources/SelectionTestCase.js

 if (!window.eventSender || !window.testRunner) {
     alert('This test needs to be run in DRT, to get results!');
 }
 
 var svgRoot = 0;
 
 // Map 'point' into absolute coordinates, usable for eventSender
 function transformPoint(point, matrix) {
     return point.matrixTransform(matrix);
 }
@@ skipping 11 matching lines @@
 
     var newRect = svgRoot.createSVGRect();
     newRect.x = topLeft.x;
     newRect.y = topLeft.y;
     newRect.width = bottomRight.x - topLeft.x;
     newRect.height = bottomRight.y - topLeft.y;
     return newRect;
 }
 
 function toAbsoluteCoordinates(point, element) {
-    return transformPoint(point, document.rootElement.getTransformToElement(element));
+    // getScreenCTM() returns the transformation matrix from current user units (i.e., after application of the ‘transform’ property)
+    // to the parent user agent's notice of a "pixel".
+    return transformPoint(point, element.getScreenCTM());
 }
 
 // Select a range of characters in text element 'id', from the start position of the 'start' character to the end position of the 'end' character
 function selectRange(id, start, end, expectedText) {
     var element = document.getElementById(id);
     var startExtent = element.getExtentOfChar(start);
     var endExtent = element.getExtentOfChar(end);
 
     var startPos = element.getStartPositionOfChar(start);
     var endPos = element.getEndPositionOfChar(end);
@@ skipping 72 matching lines @@
         var textElement = document.createElementNS("http://www.w3.org/2000/svg", "svg:text");
         textElement.setAttribute("x", "0");
         textElement.setAttribute("y", "35");
         textElement.setAttribute("fill", "red");
         textElement.setAttribute("transform", "scale(0.5)");
         textElement.setAttribute("font-size", "8");
         textElement.textContent = "Expected '" + expectedText + "' to be selected, got: '" + actualText + "'";
         document.getElementById("container").appendChild(textElement);
     }
 }