Prevent default actions for JS-generated mouse events other than click

LayoutTests/fast/dom/HTMLSelectElement/remove-element-from-within-focus-handler-crash.html

Index: LayoutTests/fast/dom/HTMLSelectElement/remove-element-from-within-focus-handler-crash.html
diff --git a/LayoutTests/fast/dom/HTMLSelectElement/remove-element-from-within-focus-handler-crash.html b/LayoutTests/fast/dom/HTMLSelectElement/remove-element-from-within-focus-handler-crash.html
index 5ea3a5772bf486c38e3978a4dee52bb1e4a8a2a4..5d039fa2c312bab100d71b55b522109b88c68b45 100644
--- a/LayoutTests/fast/dom/HTMLSelectElement/remove-element-from-within-focus-handler-crash.html
+++ b/LayoutTests/fast/dom/HTMLSelectElement/remove-element-from-within-focus-handler-crash.html
@@ -2,13 +2,15 @@
     <option>Clicking on this select element should not crash</option>
 </select>
 <h2>Layout test for <a href='https://bugs.webkit.org/show_bug.cgi?id=23858'>bug 23858</a></h2>
-<p>If this page is displayed without crashing then the test has passed.</p>
+<p>If the select can be clicked without crashing then the test has passed.</p>
 <script>
-    if (window.testRunner)
+     if (window.testRunner)
         testRunner.dumpAsText();
 
     var select = document.getElementById('bomb');
-    var mouseEvent = document.createEvent("MouseEvents");
-    mouseEvent.initMouseEvent("mousedown", true, true, document.defaultView, 1, select.offsetLeft + 1, select.offsetTop + 1, select.offsetLeft + 1, select.offsetTop + 1, false, false, false, false, 0, document);
-    select.dispatchEvent(mouseEvent);
+    var rect = select.getBoundingClientRect();
+    if (window.eventSender) {
+        eventSender.mouseMoveTo(rect.left + 1, rect.top + 1);
+        eventSender.mouseDown(0);
+    }
 </script>