Remove IFX_SystemHandler.

xfa/fwl/core/fwl_sdadapterimp.cpp

Index: xfa/fwl/core/fwl_sdadapterimp.cpp
diff --git a/xfa/fwl/core/fwl_sdadapterimp.cpp b/xfa/fwl/core/fwl_sdadapterimp.cpp
index 9732414ea13536809f4ed199b877841f5a06cff0..76cbad6b86ea1d7b962badd5b96a63e68c3aee04 100644
--- a/xfa/fwl/core/fwl_sdadapterimp.cpp
+++ b/xfa/fwl/core/fwl_sdadapterimp.cpp
@@ -127,10 +127,6 @@ FWL_ERR CFWL_SDAdapterWidgetMgr::UpdateMenu(IFWL_Menu* pMenu,
                                             int32_t iType) {
   return FWL_ERR_Succeeded;
 }
-int32_t CFWL_SDAdapterWidgetMgr::TrackPopupMenu(IFWL_Menu* pMenu,
-                                                IFWL_MenuDP* pMenuData) {
-  return 0;
-}
 FWL_ERR CFWL_SDAdapterWidgetMgr::SetMessageHook(IFWL_AdapterMessageHook* hook) {
   return FWL_ERR_Succeeded;
 }