Convert //ash from scoped_ptr to std::unique_ptr

ash/host/ash_window_tree_host_x11.h

Index: ash/host/ash_window_tree_host_x11.h
diff --git a/ash/host/ash_window_tree_host_x11.h b/ash/host/ash_window_tree_host_x11.h
index 0c36d03351de6a6f2a8689da3910dcad96aa2401..f26181ea63099584da2da277c58fe40feff359db 100644
--- a/ash/host/ash_window_tree_host_x11.h
+++ b/ash/host/ash_window_tree_host_x11.h
@@ -5,11 +5,12 @@
 #ifndef ASH_HOST_ASH_WINDOW_TREE_HOST_X11_H_
 #define ASH_HOST_ASH_WINDOW_TREE_HOST_X11_H_
 
+#include <memory>
+
 #include "ash/ash_export.h"
 #include "ash/host/ash_window_tree_host.h"
 #include "ash/host/transformer_helper.h"
 #include "base/macros.h"
-#include "base/memory/scoped_ptr.h"
 #include "ui/aura/env_observer.h"
 #include "ui/aura/window_tree_host_x11.h"
 
@@ -30,7 +31,7 @@ class ASH_EXPORT AshWindowTreeHostX11 : public AshWindowTreeHost,
   bool ConfineCursorToRootWindow() override;
   void UnConfineCursor() override;
   void SetRootWindowTransformer(
-      scoped_ptr<RootWindowTransformer> transformer) override;
+      std::unique_ptr<RootWindowTransformer> transformer) override;
   gfx::Insets GetHostInsets() const override;
   aura::WindowTreeHost* AsWindowTreeHost() override;
   void PrepareForShutdown() override;
@@ -62,7 +63,7 @@ class ASH_EXPORT AshWindowTreeHostX11 : public AshWindowTreeHost,
   void SetCrOSTapPaused(bool state);
 #endif
 
-  scoped_ptr<XID[]> pointer_barriers_;
+  std::unique_ptr<XID[]> pointer_barriers_;
 
   TransformerHelper transformer_helper_;