Keep the mouse cursor within desktop

ui/aura/env.cc

Index: ui/aura/env.cc
diff --git a/ui/aura/env.cc b/ui/aura/env.cc
index 32ead2bce410fd08bc3d093b2f597240ba0a71e3..9f1e1ec1638a2be57beb1a45a8c7a8fabe5bfab6 100644
--- a/ui/aura/env.cc
+++ b/ui/aura/env.cc
@@ -9,10 +9,6 @@
 #include "ui/aura/window.h"
 #include "ui/gfx/compositor/compositor.h"
 
-#if defined(USE_X11)
-#include "ui/aura/monitor_change_observer_x11.h"
-#endif
-
 namespace aura {
 
 // static
@@ -25,9 +21,6 @@ Env::Env()
     : mouse_button_flags_(0),
       stacking_client_(NULL),
       monitor_manager_(new internal::SingleMonitorManager)
-#if defined(USE_X11)
-    , monitor_change_observer_(new MonitorChangeObserverX11())
-#endif
 {
 #if !defined(OS_MACOSX)
   dispatcher_.reset(CreateDispatcher());