Remove usages of XInternAtom

ui/base/dragdrop/os_exchange_data_provider_aurax11.h

Index: ui/base/dragdrop/os_exchange_data_provider_aurax11.h
diff --git a/ui/base/dragdrop/os_exchange_data_provider_aurax11.h b/ui/base/dragdrop/os_exchange_data_provider_aurax11.h
index fbf19bc6cd1db3c479d3252fef60ecb16648fdef..9ffe068cd44618b1e419733e00ef8e42eb6d602d 100644
--- a/ui/base/dragdrop/os_exchange_data_provider_aurax11.h
+++ b/ui/base/dragdrop/os_exchange_data_provider_aurax11.h
@@ -23,7 +23,6 @@
 #include "ui/events/platform/platform_event_dispatcher.h"
 #include "ui/gfx/geometry/vector2d.h"
 #include "ui/gfx/image/image_skia.h"
-#include "ui/gfx/x/x11_atom_cache.h"
 #include "url/gurl.h"
 
 namespace ui {
@@ -129,8 +128,6 @@ class UI_BASE_EXPORT OSExchangeDataProviderAuraX11
 
   ::Window x_window_;
 
-  X11AtomCache atom_cache_;
-
   // A representation of data. This is either passed to us from the other
   // process, or built up through a sequence of Set*() calls. It can be passed
   // to |selection_owner_| when we take the selection.