Desktop aura: Put x11 cache in aura, instead of ui/base/x/.

ui/aura/env.h

Index: ui/aura/env.h
diff --git a/ui/aura/env.h b/ui/aura/env.h
index 033456561f3dc2451bd78d50b9c5fb07dad52487..6ffb74fa6d2e9a671bf48a14f84d9d6f49e8f054 100644
--- a/ui/aura/env.h
+++ b/ui/aura/env.h
@@ -12,6 +12,10 @@
 #include "ui/aura/aura_export.h"
 #include "ui/aura/client/stacking_client.h"
 
+#if defined(USE_X11)
+#include "ui/aura/x11_atom_cache.h"
+#endif
+
 namespace aura {
 
 class EnvObserver;
@@ -55,6 +59,12 @@ class AURA_EXPORT Env {
   MonitorManager* monitor_manager() { return monitor_manager_.get(); }
   void SetMonitorManager(MonitorManager* monitor_manager);
 
+#if defined(USE_X11)
+  // Gets the X11 atom cache. This must not persist the cache across
+  // Env::DeleteInstance() calls.
+  X11AtomCache* atom_cache() { return &atom_cache_; }
+#endif
+
   // Returns the native event dispatcher. The result should only be passed to
   // MessageLoopForUI::RunWithDispatcher() or
   // MessageLoopForUI::RunAllPendingWithDispatcher(), or used to dispatch
@@ -83,6 +93,7 @@ class AURA_EXPORT Env {
 
 #if defined(USE_X11)
   scoped_ptr<internal::MonitorChangeObserverX11> monitor_change_observer_;
+  X11AtomCache atom_cache_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(Env);