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 23e6a91eb3f3ad81918a6226612659f4c8a7da32..4d1149100f32fb5e70836a9a48eb0ebb9bb492e2 100644
--- a/ash/common/shelf/shelf_layout_manager.h
+++ b/ash/common/shelf/shelf_layout_manager.h
@@ -280,6 +280,10 @@ 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);