Fix the content_browsertests everywhere maybe.

ash/shell.h

Index: ash/shell.h
diff --git a/ash/shell.h b/ash/shell.h
index bc86059a0e120670429be4e43ce22be551425c63..8978ce3ec9c73ec3b2a1d8ddd834ddb5c0806112 100644
--- a/ash/shell.h
+++ b/ash/shell.h
@@ -33,7 +33,6 @@ class Window;
 namespace client {
 class ActivationClient;
 class FocusClient;
-class StackingClient;
 class UserActionClient;
 }
 }
@@ -429,8 +428,6 @@ class ASH_EXPORT Shell
   }
 #endif  // defined(OS_CHROMEOS)
 
- aura::client::StackingClient* stacking_client();
-
  RootWindowHostFactory* root_window_host_factory() {
    return root_window_host_factory_.get();
  }
@@ -511,7 +508,6 @@ class ASH_EXPORT Shell
 
   scoped_ptr<internal::AppListController> app_list_controller_;
 
-  scoped_ptr<aura::client::StackingClient> stacking_client_;
   scoped_ptr<internal::ActivationController> activation_controller_;
   scoped_ptr<internal::CaptureController> capture_controller_;
   scoped_ptr<internal::DragDropController> drag_drop_controller_;