Cleanup unneeded FWL theme code.

xfa/fwl/theme/cfwl_pushbuttontp.cpp

Index: xfa/fwl/theme/cfwl_pushbuttontp.cpp
diff --git a/xfa/fwl/theme/cfwl_pushbuttontp.cpp b/xfa/fwl/theme/cfwl_pushbuttontp.cpp
index cf9991e0f447822f03cd5b25f96ca8cd8dfd5822..982a6f4b6dad8c867dd567226d00507a6c54767d 100644
--- a/xfa/fwl/theme/cfwl_pushbuttontp.cpp
+++ b/xfa/fwl/theme/cfwl_pushbuttontp.cpp
@@ -25,10 +25,9 @@ bool CFWL_PushButtonTP::IsValidWidget(IFWL_Widget* pWidget) {
   return pWidget && pWidget->GetClassID() == FWL_Type::PushButton;
 }
 uint32_t CFWL_PushButtonTP::SetThemeID(IFWL_Widget* pWidget,
-                                       uint32_t dwThemeID,
-                                       FX_BOOL bChildren) {
+                                       uint32_t dwThemeID) {
   SetThemeData(FWL_GetThemeColor(dwThemeID));
-  return CFWL_WidgetTP::SetThemeID(pWidget, dwThemeID, bChildren);
+  return CFWL_WidgetTP::SetThemeID(pWidget, dwThemeID);
 }
 FX_BOOL CFWL_PushButtonTP::DrawBackground(CFWL_ThemeBackground* pParams) {
   switch (pParams->m_iPart) {