Revert of Support modal windows

athena/screen/public/screen_manager.h

Index: athena/screen/public/screen_manager.h
diff --git a/athena/screen/public/screen_manager.h b/athena/screen/public/screen_manager.h
index 11dda1f7ad87a571121a4ea91935d432d858fea4..e2637820ece499b8b7fda62bc0caa57363c268b6 100644
--- a/athena/screen/public/screen_manager.h
+++ b/athena/screen/public/screen_manager.h
@@ -29,37 +29,11 @@
     // True if the container can activate its child window.
     bool can_activate_children;
 
-    // True if the container will block evnets from containers behind it.
-    bool block_events;
+    // True if the container will grab all of input events.
+    bool grab_inputs;
 
     // Defines the z_order priority of the container.
     int z_order_priority;
-
-    // True if this container should be used as a default parent.
-    bool default_parent;
-
-    // The container priority used to open modal dialog window
-    // created with this container as a transient parent  (Note: A modal window
-    // should
-    // use a trnasient parent, not a direct parent, or no transient parent.)
-    //
-    // Default is -1, and it will fallback to the container behind this
-    // container,
-    // that has the modal container proiroty.
-    //
-    // The modal container for modal window is selected as follows.
-    // 1) a window must be created with |aura::client::kModalKey| property
-    //   without explicit parent set.
-    // 2.a) If aura::client::kAlwaysOnTopKey is NOT set, it uses the stand flow
-    //   described above. (fallback to containers behind this).
-    // 2.b) If aura::client::kAlwaysOnTopKey is set, it searches the top most
-    //   container which has |modal_container_priority| != -1.
-    // 3) Look for the container with |modal_container_priority|, and create
-    //   one if it doesn't exist.
-    //
-    // Created modal container will self destruct if last modal window
-    // is deleted.
-    int modal_container_priority;
   };
 
   // Creates, returns and deletes the singleton object of the ScreenManager
@@ -69,6 +43,11 @@
   static void Shutdown();
 
   virtual ~ScreenManager() {}
+
+  // Creates the container window that is used when creating a normal
+  // widget without specific parent.
+  virtual aura::Window* CreateDefaultContainer(
+      const ContainerParams& params) = 0;
 
   // Creates the container window on the screen.
   virtual aura::Window* CreateContainer(const ContainerParams& params) = 0;