Fix mouse position to truncate the coordinate for mouseMoveTo(...)

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 45 matching lines @@
 
         startPos = transformPoint(startPos, scaleMatrix);
         endPos = transformPoint(endPos, scaleMatrix);
 
         startExtent = transformRect(startExtent, scaleMatrix);
         endExtent = transformRect(endExtent, scaleMatrix);
     }
 
     if (window.eventSender) {
         // Trigger 'partial glyph selection' code, by adjusting the end x position by half glyph width
-        var xOld = endPos.x;
+        var xOldStart = startPos.x;
+        var xOldEnd = endPos.x;
         endPos.x -= endExtent.width / 2 - 1;
 
+        // Round the points "inwards" to avoid being affected by the truncation
+        // taking place in eventSender.mouseMoveTo(...).
+        startPos.x = Math.ceil(startPos.x);
+
         var absStartPos = toAbsoluteCoordinates(startPos, element);
         var absEndPos = toAbsoluteCoordinates(endPos, element);
 
-        // Round the points "inwards" to avoid being affected by the truncation
-        // taking place in eventSender.mouseMoveTo(...).
-        absStartPos.x = Math.ceil(absStartPos.x);
-        absEndPos.x = Math.floor(absEndPos.x);
-
         // Move to selection origin and hold down mouse
         eventSender.mouseMoveTo(absStartPos.x, absStartPos.y);
         eventSender.mouseDown();
 
         // Move again to start selection
         eventSender.mouseMoveTo(absStartPos.x, absStartPos.y);
 
         // Move to end location and release mouse
         eventSender.mouseMoveTo(absEndPos.x, absEndPos.y);
         eventSender.mouseUp();
 
-        endPos.x = xOld;
+        startPos.x = xOldStart;
+        endPos.x = xOldEnd;
     }
 
     // Mark start position using a green line
     var startLineElement = document.createElementNS("http://www.w3.org/2000/svg", "svg:line");
     startLineElement.setAttribute("x1", startPos.x);
     startLineElement.setAttribute("y1", startExtent.y);
     startLineElement.setAttribute("x2", startPos.x);
     startLineElement.setAttribute("y2", startExtent.height + 1);
     startLineElement.setAttribute("stroke", "green");
     document.getElementById("container").appendChild(startLineElement);
@@ skipping 23 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);
     }
 }