Move shelf item tooltip flag from delegate to item.

ash/common/wm/panels/panel_layout_manager.cc

Index: ash/common/wm/panels/panel_layout_manager.cc
diff --git a/ash/common/wm/panels/panel_layout_manager.cc b/ash/common/wm/panels/panel_layout_manager.cc
index d5e3e63981e8e98c6dff188b50645025d1a760b5..37a3c646d7dfee563eba175432aa92c064c77e16 100644
--- a/ash/common/wm/panels/panel_layout_manager.cc
+++ b/ash/common/wm/panels/panel_layout_manager.cc
@@ -340,7 +340,7 @@ void PanelLayoutManager::OnWindowAddedToLayout(WmWindow* child) {
   if (in_add_window_)
     return;
   base::AutoReset<bool> auto_reset_in_add_window(&in_add_window_, true);
-  if (!child->GetWindowState()->panel_attached()) {
+  if (!child->GetBoolProperty(WmWindowProperty::PANEL_ATTACHED)) {
     // This should only happen when a window is added to panel container as a
     // result of bounds change from within the application during a drag.
     // If so we have already stopped the drag and should reparent the panel