Kill dead IFWL_*::Initialize() variants dead.

xfa/src/fwl/src/core/fwl_widgetimp.cpp

Index: xfa/src/fwl/src/core/fwl_widgetimp.cpp
diff --git a/xfa/src/fwl/src/core/fwl_widgetimp.cpp b/xfa/src/fwl/src/core/fwl_widgetimp.cpp
index 78daae08a700eefe9d27d75227da6a92bac55669..5a5fcab17338a006a00bb5e24c120cc65c0f407d 100644
--- a/xfa/src/fwl/src/core/fwl_widgetimp.cpp
+++ b/xfa/src/fwl/src/core/fwl_widgetimp.cpp
@@ -1121,12 +1121,6 @@ IFWL_Custom* IFWL_Custom::Create() {
 }
 IFWL_Custom::IFWL_Custom() {
 }
-FWL_ERR IFWL_Custom::Initialize(IFWL_Widget* pOuter) {
-  CFWL_Custom* pCustomImpl = new CFWL_Custom(pOuter);
-  SetImpl(pCustomImpl);
-  pCustomImpl->SetInterface(this);
-  return pCustomImpl->Initialize();
-}
 FWL_ERR IFWL_Custom::Initialize(const CFWL_WidgetImpProperties& properties,
                                 IFWL_Widget* pOuter) {
   CFWL_Custom* pCustomImpl = new CFWL_Custom(properties, pOuter);