Makes RootWindowController window creation in terms of common types

ui/wm/core/visibility_controller.h

Index: ui/wm/core/visibility_controller.h
diff --git a/ui/wm/core/visibility_controller.h b/ui/wm/core/visibility_controller.h
index 78c15adf46d384811d6bd8a2973f5b4e1a8c8386..cb50673a86691361fdba5ea773384e68b87191a7 100644
--- a/ui/wm/core/visibility_controller.h
+++ b/ui/wm/core/visibility_controller.h
@@ -73,8 +73,8 @@ class WM_EXPORT SuspendChildWindowVisibilityAnimations {
 // the animation stays enabled.
 void WM_EXPORT SetWindowVisibilityChangesAnimated(aura::Window* window);
 
-// Enable visibiilty change animation for all children of the |window|.
-// Tyically applied to a container whose child windows should be animated
+// Enable visibility change animation for all children of the |window|.
+// Typically applied to a container whose child windows should be animated
 // when their visibility changes.
 void WM_EXPORT SetChildWindowVisibilityChangesAnimated(
     aura::Window* window);