Convert FWL_ERR into an enum class.

xfa/fxfa/app/xfa_fwladapter.cpp

Index: xfa/fxfa/app/xfa_fwladapter.cpp
diff --git a/xfa/fxfa/app/xfa_fwladapter.cpp b/xfa/fxfa/app/xfa_fwladapter.cpp
index 5821a729eb4fab062dfb3de4dbc3f7bf6e71ea9f..febbb2e9974264f4a6e06e9bf23714c9e8cc1af4 100644
--- a/xfa/fxfa/app/xfa_fwladapter.cpp
+++ b/xfa/fxfa/app/xfa_fwladapter.cpp
@@ -9,15 +9,15 @@
 #include "xfa/fxfa/app/xfa_fffield.h"
 #include "xfa/fxfa/include/xfa_ffdoc.h"
 
-FWL_ERR CXFA_FWLAdapterWidgetMgr::RepaintWidget(IFWL_Widget* pWidget,
-                                                const CFX_RectF* pRect) {
+FWL_Error CXFA_FWLAdapterWidgetMgr::RepaintWidget(IFWL_Widget* pWidget,
+                                                  const CFX_RectF* pRect) {
   if (!pWidget)
-    return FWL_ERR_Indefinite;
+    return FWL_Error::Indefinite;
   CXFA_FFField* pField = (CXFA_FFField*)pWidget->GetPrivateData(pWidget);
   if (!pField)
-    return FWL_ERR_Indefinite;
+    return FWL_Error::Indefinite;
   pField->AddInvalidateRect(nullptr);
-  return FWL_ERR_Succeeded;
+  return FWL_Error::Succeeded;
 }
 
 FX_BOOL CXFA_FWLAdapterWidgetMgr::GetPopupPos(IFWL_Widget* pWidget,