Run event executor on the ui thread to remove the need to explicitly XFlush() the XTest calls.

base/message_loop.h

Index: base/message_loop.h
diff --git a/base/message_loop.h b/base/message_loop.h
index d23899784b3a27d33d166a118d6e579d96e400af..58306a720825050580b33b2a439986e2bb72156c 100644
--- a/base/message_loop.h
+++ b/base/message_loop.h
@@ -24,6 +24,7 @@
 #include "base/message_pump_libevent.h"
 #if !defined(OS_MACOSX)
 #include "base/message_pump_glib.h"
+typedef struct _XDisplay Display;
 #endif
 #endif
 #if defined(TOUCH_UI)
@@ -508,6 +509,10 @@ class MessageLoopForUI : public MessageLoop {
   void DidProcessMessage(const MSG& message);
 #endif  // defined(OS_WIN)
 
+#if defined(OS_POSIX) && !defined(OS_MACOSX)
+  Display* get_display();
+#endif
+
 #if !defined(OS_MACOSX)
   // Please see message_pump_win/message_pump_glib for definitions of these
   // methods.