Cleanup unused methods and return values in FWL code.

xfa/fwl/core/ifwl_pushbutton.h

Index: xfa/fwl/core/ifwl_pushbutton.h
diff --git a/xfa/fwl/core/ifwl_pushbutton.h b/xfa/fwl/core/ifwl_pushbutton.h
index d5ada29e41908389ceeb4b1361bb0693f1414ed4..8906aa898f0d6a0c09d9ce7fad36f1a789288b25 100644
--- a/xfa/fwl/core/ifwl_pushbutton.h
+++ b/xfa/fwl/core/ifwl_pushbutton.h
@@ -11,7 +11,6 @@
 #include "xfa/fwl/core/ifwl_dataprovider.h"
 #include "xfa/fwl/core/ifwl_widget.h"
 
-#define FWL_CLASS_PushButton L"FWL_PUSHBUTTON"
 #define FWL_STYLEEXT_PSB_Left (0L << 0)
 #define FWL_STYLEEXT_PSB_Center (1L << 0)
 #define FWL_STYLEEXT_PSB_Right (2L << 0)
@@ -45,10 +44,9 @@ class IFWL_PushButton : public IFWL_Widget {
   ~IFWL_PushButton() override;
 
   // IFWL_Widget
-  FWL_Error GetClassName(CFX_WideString& wsClass) const override;
   FWL_Type GetClassID() const override;
   FWL_Error Initialize() override;
-  FWL_Error Finalize() override;
+  void Finalize() override;
   FWL_Error GetWidgetRect(CFX_RectF& rect, FX_BOOL bAutoSize = FALSE) override;
   void SetStates(uint32_t dwStates, FX_BOOL bSet = TRUE) override;
   FWL_Error Update() override;