process all ui events before posting closure because menu depends

chrome/browser/automation/ui_controls_aurawin.cc

Index: chrome/browser/automation/ui_controls_aurawin.cc
diff --git a/chrome/browser/automation/ui_controls_aurawin.cc b/chrome/browser/automation/ui_controls_aurawin.cc
index 50e5f874ed99f39a5ccf54c75123a79130e30d13..31c92b48861c67e5fc2183dcf00d9e4fbc08293f 100644
--- a/chrome/browser/automation/ui_controls_aurawin.cc
+++ b/chrome/browser/automation/ui_controls_aurawin.cc
@@ -5,6 +5,7 @@
 #include "chrome/browser/automation/ui_controls.h"
 
 #include "base/logging.h"
+#include "base/message_loop.h"
 #include "chrome/browser/automation/ui_controls_internal.h"
 #include "ui/aura/desktop.h"
 #include "ui/views/view.h"
@@ -69,4 +70,9 @@ void MoveMouseToCenterAndPress(views::View* view,
   SendMouseEventsNotifyWhenDone(button, state, task);
 }
 
+void RunClosureAfterAllPendingUIEvents(const base::Closure& task) {
+  // On windows, posting UI events is synchronous so just post the closure.
+  MessageLoopForUI::current()->PostTask(FROM_HERE, task);
+}
+
 }  // namespace ui_controls