Add WindowPinType property on arua::Window

ash/mus/window_manager.cc

Index: ash/mus/window_manager.cc
diff --git a/ash/mus/window_manager.cc b/ash/mus/window_manager.cc
index 7daf1484620f7e185a7216c841d714914d680058..df3259b0374dfb3f2c7ba5774b642fe75d931276 100644
--- a/ash/mus/window_manager.cc
+++ b/ash/mus/window_manager.cc
@@ -89,6 +89,9 @@ WindowManager::WindowManager(service_manager::Connector* connector,
       kShelfItemTypeKey, ui::mojom::WindowManager::kShelfItemType_Property,
       base::Bind(&IsValidShelfItemType));
   property_converter_->RegisterProperty(
+      kWindowPinTypeKey, ui::mojom::WindowManager::kWindowPinType_Property,
+      base::Bind(&IsValidWindowPinType));
+  property_converter_->RegisterProperty(
       ::wm::kShadowElevationKey,
       ui::mojom::WindowManager::kShadowElevation_Property,
       base::Bind(&::wm::IsValidShadowElevation));