Fix the content_browsertests everywhere maybe.

ui/aura/env.h

Index: ui/aura/env.h
diff --git a/ui/aura/env.h b/ui/aura/env.h
index 24d7f4fa6caecf06d2e1aa360112ebe371227db3..ae4f1a6f17cb544e00a32e8596a628f6d6da4477 100644
--- a/ui/aura/env.h
+++ b/ui/aura/env.h
@@ -9,7 +9,6 @@
 #include "base/message_loop.h"
 #include "base/observer_list.h"
 #include "ui/aura/aura_export.h"
-#include "ui/aura/client/stacking_client.h"
 #include "ui/base/events/event_handler.h"
 #include "ui/base/events/event_target.h"
 #include "ui/gfx/point.h"
@@ -64,11 +63,6 @@ class AURA_EXPORT Env : public ui::EventTarget {
   bool render_white_bg() const { return render_white_bg_; }
   void set_render_white_bg(bool value) { render_white_bg_ = value; }
 
-  client::StackingClient* stacking_client() { return stacking_client_; }
-  void set_stacking_client(client::StackingClient* stacking_client) {
-    stacking_client_ = stacking_client;
-  }
-
   // Returns the native event dispatcher. The result should only be passed to
   // base::RunLoop(dispatcher), or used to dispatch an event by
   // |Dispatch(const NativeEvent&)| on it. It must never be stored.
@@ -102,7 +96,6 @@ class AURA_EXPORT Env : public ui::EventTarget {
   gfx::Point last_mouse_location_;
   bool is_touch_down_;
   bool render_white_bg_;
-  client::StackingClient* stacking_client_;
 
 #if defined(USE_X11)
   DeviceListUpdaterAuraX11 device_list_updater_aurax11_;