Remove CLASSHASH defines in favour of an enum class.

xfa/fwl/theme/cfwl_monthcalendartp.cpp

Index: xfa/fwl/theme/cfwl_monthcalendartp.cpp
diff --git a/xfa/fwl/theme/cfwl_monthcalendartp.cpp b/xfa/fwl/theme/cfwl_monthcalendartp.cpp
index fac318f69db4ca3bda1532e1ecf64b2af0196f05..d04ebb16d20a19a9019b2db21006b260d007cf73 100644
--- a/xfa/fwl/theme/cfwl_monthcalendartp.cpp
+++ b/xfa/fwl/theme/cfwl_monthcalendartp.cpp
@@ -53,13 +53,13 @@ CFWL_MonthCalendarTP::CFWL_MonthCalendarTP() {
   m_pThemeData = new MCThemeData;
   SetThemeData(0);
 }
+
 CFWL_MonthCalendarTP::~CFWL_MonthCalendarTP() {
   delete m_pThemeData;
 }
-FX_BOOL CFWL_MonthCalendarTP::IsValidWidget(IFWL_Widget* pWidget) {
-  if (!pWidget)
-    return FALSE;
-  return pWidget->GetClassID() == FWL_CLASSHASH_MonthCalendar;
+
+bool CFWL_MonthCalendarTP::IsValidWidget(IFWL_Widget* pWidget) {
+  return pWidget && pWidget->GetClassID() == FWL_Type::MonthCalendar;
 }
 uint32_t CFWL_MonthCalendarTP::SetThemeID(IFWL_Widget* pWidget,
                                           uint32_t dwThemeID,