Update shelf when overlapping dragged windows exist

ash/wm/dock/docked_window_layout_manager.cc

Index: ash/wm/dock/docked_window_layout_manager.cc
diff --git a/ash/wm/dock/docked_window_layout_manager.cc b/ash/wm/dock/docked_window_layout_manager.cc
index b3c9ebece7c8fdf7a5bc3e47077cb12154fb0d99..a224a12844aa17948484be0c9debad2db924f49a 100644
--- a/ash/wm/dock/docked_window_layout_manager.cc
+++ b/ash/wm/dock/docked_window_layout_manager.cc
@@ -483,6 +483,12 @@ void DockedWindowLayoutManager::SetChildBounds(
     const gfx::Rect& requested_bounds) {
   // Whenever one of our windows is moved or resized enforce layout.
   SetChildBoundsDirect(child, requested_bounds);
+  if (IsPopupOrTransient(child))
+    return;
+  ShelfLayoutManager* shelf_layout = internal::ShelfLayoutManager::ForLauncher(
+      dock_container_);
+  if (shelf_layout)
+    shelf_layout->UpdateVisibilityState();
 }
 
 ////////////////////////////////////////////////////////////////////////////////