Remove CLASSHASH defines in favour of an enum class.

xfa/fwl/theme/cfwl_checkboxtp.cpp

Index: xfa/fwl/theme/cfwl_checkboxtp.cpp
diff --git a/xfa/fwl/theme/cfwl_checkboxtp.cpp b/xfa/fwl/theme/cfwl_checkboxtp.cpp
index 78d829f8b035b7d084158496d63d9eef8ffbf263..9a10c60a3dfdf5e242a3854279007a327fe70d27 100644
--- a/xfa/fwl/theme/cfwl_checkboxtp.cpp
+++ b/xfa/fwl/theme/cfwl_checkboxtp.cpp
@@ -40,9 +40,10 @@ CFWL_CheckBoxTP::~CFWL_CheckBoxTP() {
   }
 }
 
-FX_BOOL CFWL_CheckBoxTP::IsValidWidget(IFWL_Widget* pWidget) {
-  return pWidget && pWidget->GetClassID() == FWL_CLASSHASH_CheckBox;
+bool CFWL_CheckBoxTP::IsValidWidget(IFWL_Widget* pWidget) {
+  return pWidget && pWidget->GetClassID() == FWL_Type::CheckBox;
 }
+
 uint32_t CFWL_CheckBoxTP::SetThemeID(IFWL_Widget* pWidget,
                                      uint32_t dwThemeID,
                                      FX_BOOL bChildren) {