Explicit container priority

athena/screen/public/screen_manager.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef ATHENA_SCREEN_PUBLIC_SCREEN_MANAGER_H_
 #define ATHENA_SCREEN_PUBLIC_SCREEN_MANAGER_H_
 
 #include <string>
 
 #include "athena/athena_export.h"
@@ skipping 11 matching lines @@
 }
 
 namespace athena {
 
 // Mananges basic UI components on the screen such as background, and provide
 // API for other UI components, such as window manager, home card, to
 // create and manage their windows on the screen.
 class ATHENA_EXPORT ScreenManager {
  public:
   struct ContainerParams {
-    ContainerParams(const std::string& name);
+    ContainerParams(const std::string& name, int z_order_priority);
     std::string name;
 
     // True if the container can activate its child window.
     bool can_activate_children;
+
+    // Defines the z_order priority of the container.
+    int z_order_priority;
   };
 
   // Creates, returns and deletes the singleton object of the ScreenManager
   // implementation.
   static ScreenManager* Create(aura::Window* root);
   static ScreenManager* Get();
   static void Shutdown();
 
   virtual ~ScreenManager() {}
 
@@ skipping 12 matching lines @@
   virtual void SetBackgroundImage(const gfx::ImageSkia& image) = 0;
 
   // Create a focus rules.
   // TODO(oshima): Make this virtual function.
   static wm::FocusRules* CreateFocusRules();
 };
 
 }  // namespace athena
 
 #endif  // ATHENA_SCREEN_PUBLIC_SCREEN_MANAGER_H_