aura: Require explicit ownership of the Env instance.

ash/test/ash_interactive_ui_test_base.h

Index: ash/test/ash_interactive_ui_test_base.h
diff --git a/ash/test/ash_interactive_ui_test_base.h b/ash/test/ash_interactive_ui_test_base.h
index 742e46fafa88a9322ed1301d875d6c19cc2ef9f7..bf2f66726066d385c2875b7f9aed802b53fadf61 100644
--- a/ash/test/ash_interactive_ui_test_base.h
+++ b/ash/test/ash_interactive_ui_test_base.h
@@ -9,6 +9,10 @@
 
 #include "ash/test/ash_test_base.h"
 
+namespace aura {
+class Env;
+}
+
 namespace ash {
 namespace test {
 
@@ -23,6 +27,7 @@ class AshInteractiveUITestBase : public AshTestBase {
   void TearDown() override;
 
  private:
+  scoped_ptr<aura::Env> env_;
   DISALLOW_COPY_AND_ASSIGN(AshInteractiveUITestBase);
 };