SELECT element: Ignore synthetic events.

third_party/WebKit/LayoutTests/fast/forms/resources/picker-common.js

 window.jsTestIsAsync = true;
 
 var popupWindow = null;
 
 var popupOpenCallback = null;
 
 function popupOpenCallbackWrapper() {
     popupWindow.removeEventListener("didOpenPicker", popupOpenCallbackWrapper);
     // We need some delay.  Without it, testRunner.notifyDone() freezes.
     // See crbug.com/562311.
@@ skipping 26 matching lines @@
 // |callback| is called if we successfully open the picker UI. However it is
 // called only for the following types:
 // - menulist SELECT on Windows, Linux, and CrOS
 // - INPUT color with DATALIST
 // - INPUT date/datetime-local/month/week
 function openPicker(element, callback, errorCallback) {
     rootWindow().moveTo(window.screenX, window.screenY);
     element.offsetTop; // Force to lay out
     element.focus();
     if (element.tagName === "SELECT") {
-        sendKey(element, "Down", false, true);
+        eventSender.keyDown("downArrow", ["altKey"]);
     } else if (element.tagName === "INPUT") {
         if (element.type === "color") {
             element.focus();
             eventSender.keyDown(" ");
         } else {
             sendKey(element, "Down", false, true);
         }
     }
     popupWindow = window.internals.pagePopupWindow;
     if (typeof callback === "function" && popupWindow)
@@ skipping 22 matching lines @@
         // ShellViewMsg_SetTestConfiguration IPC arrives.
         rootWindow().moveTo(window.screenX, window.screenY);
         callback();
     }).bind(this, callback);
     try {
         popupWindow.addEventListener("didOpenPicker", popupOpenCallbackWrapper, false);
     } catch(e) {
         debug(e.name);
     }
 }