Selection Action mode triggered like a context menu

ui/base/ui_base_types.h

Index: ui/base/ui_base_types.h
diff --git a/ui/base/ui_base_types.h b/ui/base/ui_base_types.h
index 7eaf0e0b1693ab60acbea7e13219dce1ccb9fcc4..975a82d712bbbf068ee9ed693ada510c14357ab2 100644
--- a/ui/base/ui_base_types.h
+++ b/ui/base/ui_base_types.h
@@ -49,7 +49,8 @@ enum MenuSourceType {
   MENU_SOURCE_LONG_PRESS      = 5,
   MENU_SOURCE_LONG_TAP        = 6,
   MENU_SOURCE_TOUCH_HANDLE    = 7,
-  MENU_SOURCE_TYPE_LAST = MENU_SOURCE_TOUCH_HANDLE
+  MENU_SOURCE_STYLUS          = 8,
+  MENU_SOURCE_TYPE_LAST = MENU_SOURCE_STYLUS
 };
 
 UI_BASE_EXPORT MenuSourceType GetMenuSourceTypeForEvent(const ui::Event& event);