Remove usages of XInternAtom

ui/views/widget/desktop_aura/desktop_window_tree_host_x11.h

Index: ui/views/widget/desktop_aura/desktop_window_tree_host_x11.h
diff --git a/ui/views/widget/desktop_aura/desktop_window_tree_host_x11.h b/ui/views/widget/desktop_aura/desktop_window_tree_host_x11.h
index 757b7808e08cc403f11b1e573661245b8ec18c4d..c0e1763449def134e9b90d9516af60b578f56c9a 100644
--- a/ui/views/widget/desktop_aura/desktop_window_tree_host_x11.h
+++ b/ui/views/widget/desktop_aura/desktop_window_tree_host_x11.h
@@ -22,7 +22,6 @@
 #include "ui/gfx/geometry/insets.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/geometry/size.h"
-#include "ui/gfx/x/x11_atom_cache.h"
 #include "ui/views/views_export.h"
 #include "ui/views/widget/desktop_aura/desktop_window_tree_host.h"
 
@@ -289,8 +288,6 @@ class VIEWS_EXPORT DesktopWindowTreeHostX11
   // The native root window.
   ::Window x_root_window_;
 
-  ui::X11AtomCache atom_cache_;
-
   // Whether the window is mapped with respect to the X server.
   bool window_mapped_in_server_;