Move shelf item tooltip flag from delegate to item.

ash/common/wm/drag_details.cc

Index: ash/common/wm/drag_details.cc
diff --git a/ash/common/wm/drag_details.cc b/ash/common/wm/drag_details.cc
index c0a718873abdeba8e09897e968dfffaa5524c776..1f8f93be44ee8a2a2a34a67e30baa242d00a86b5 100644
--- a/ash/common/wm/drag_details.cc
+++ b/ash/common/wm/drag_details.cc
@@ -6,6 +6,7 @@
 
 #include "ash/common/wm/window_resizer.h"
 #include "ash/common/wm_window.h"
+#include "ash/common/wm_window_property.h"
 #include "ui/base/hit_test.h"
 #include "ui/compositor/layer.h"
 
@@ -60,8 +61,9 @@ DragDetails::DragDetails(WmWindow* window,
           GetSizeChangeDirectionForWindowComponent(window_component)),
       is_resizable(bounds_change != WindowResizer::kBoundsChangeDirection_None),
       source(source),
-      should_attach_to_shelf(window->GetType() == ui::wm::WINDOW_TYPE_PANEL &&
-                             window->GetWindowState()->panel_attached()) {
+      should_attach_to_shelf(
+          window->GetType() == ui::wm::WINDOW_TYPE_PANEL &&
+          window->GetBoolProperty(WmWindowProperty::PANEL_ATTACHED)) {
   wm::WindowState* window_state = window->GetWindowState();
   if ((window_state->IsNormalOrSnapped() || window_state->IsDocked()) &&
       window_state->HasRestoreBounds() && window_component == HTCAPTION) {