Revert of 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 bf2f66726066d385c2875b7f9aed802b53fadf61..742e46fafa88a9322ed1301d875d6c19cc2ef9f7 100644
--- a/ash/test/ash_interactive_ui_test_base.h
+++ b/ash/test/ash_interactive_ui_test_base.h
@@ -8,10 +8,6 @@
 #include <string>
 
 #include "ash/test/ash_test_base.h"
-
-namespace aura {
-class Env;
-}
 
 namespace ash {
 namespace test {
@@ -27,7 +23,6 @@
   void TearDown() override;
 
  private:
-  scoped_ptr<aura::Env> env_;
   DISALLOW_COPY_AND_ASSIGN(AshInteractiveUITestBase);
 };