Don't force layout for mouse event hit tests

LayoutTests/editing/selection/script-tests/click-in-margins-inside-editable-div.js

 description("Ensure cursor placement matches IE6/IE7/FF3 when clicking above/below lines in padding.")
 
 document.body.style.margin = 0;
 
 var div = document.createElement("div");
 div.style.cssText = "font-family: ahem; font-size: 20px; -webkit-text-fill-color: yellow; width: 40px; height: 80px; padding: 20px; background-color: green;";
 div.contentEditable = true;
 
 var firstText = document.createTextNode("XX");
 var firstDiv = document.createElement("div");
 firstDiv.appendChild(firstText);
 firstDiv.style.cssText = "padding-bottom: 19px; border-bottom: 1px solid pink; margin-bottom: 20px";
 div.appendChild(firstDiv);
 
 var secondText = document.createTextNode("YY");
 var secondDiv = document.createElement("div");
 secondDiv.appendChild(secondText);
 div.appendChild(secondDiv);
 
 document.body.insertBefore(div, document.body.firstChild);
 
+// Mouse events only work after an initial layout
+document.body.offsetLeft;
+
 function clickShouldResultInRange(x, y, node, offset) {
     if (window.eventSender) {
         clickAt(x, y);
         assertSelectionAt(node, offset);
     } else {
         tests.push({
             testFunction: function() { assertRange(node, offset); },
             clickString: " " + x + ", " + y }
         )
     }
@@ skipping 66 matching lines @@
 editingTest("android");
 
 // Clean up after ourselves if we're not being run in the browser
 if (window.eventSender) {
     document.body.removeChild(div);
 } else {
     runInteractiveTests();
 }
 
 var successfullyParsed = true;