x11: Prefer using ui::GetXDisplay() over getting the Display from the X11 message-pump.

ash/display/mirror_window_controller.cc

Index: ash/display/mirror_window_controller.cc
diff --git a/ash/display/mirror_window_controller.cc b/ash/display/mirror_window_controller.cc
index 1a338fec766960c1be6706bc3841889af1dbe6d0..e923219e8de52237622c6af7e71e11cf8d1631bf 100644
--- a/ash/display/mirror_window_controller.cc
+++ b/ash/display/mirror_window_controller.cc
@@ -34,6 +34,10 @@
 #include "ui/gfx/image/image_skia_operations.h"
 #include "ui/gfx/native_widget_types.h"
 
+#if defined(USE_X11)
+#include "ui/base/x/x11_util.h"
+#endif
+
 namespace ash {
 namespace internal {
 namespace {
@@ -43,8 +47,7 @@ namespace {
 void DisableInput(XID window) {
   long event_mask = ExposureMask | VisibilityChangeMask |
       StructureNotifyMask | PropertyChangeMask;
-  XSelectInput(base::MessagePumpX11::GetDefaultXDisplay(),
-               window, event_mask);
+  XSelectInput(ui::GetXDisplay(), window, event_mask);
 }
 #endif