Add ability to have active window autohide shelf

ash/common/shelf/shelf_layout_manager.h

Index: ash/common/shelf/shelf_layout_manager.h
diff --git a/ash/common/shelf/shelf_layout_manager.h b/ash/common/shelf/shelf_layout_manager.h
index 87f598a8bd6267c271b5aa9a1230e5e023772d4b..24a079b35f898e8422b49d6accd972411e3cda70 100644
--- a/ash/common/shelf/shelf_layout_manager.h
+++ b/ash/common/shelf/shelf_layout_manager.h
@@ -282,6 +282,10 @@ class ASH_EXPORT ShelfLayoutManager
   // to be hidden.
   bool IsShelfHiddenForFullscreen() const;
 
+  // Returns true if there is a fullscreen or maximized window open that causes
+  // the shelf to be autohidden.
+  bool IsShelfAutoHideForFullscreenMaximized() const;
+
   // Gesture related functions:
   void StartGestureDrag(const ui::GestureEvent& gesture);
   void UpdateGestureDrag(const ui::GestureEvent& gesture);