Cleanup unused methods and return values in FWL code.

xfa/fwl/core/ifwl_picturebox.h

Index: xfa/fwl/core/ifwl_picturebox.h
diff --git a/xfa/fwl/core/ifwl_picturebox.h b/xfa/fwl/core/ifwl_picturebox.h
index 98edd2793feac580cd3af54be8f6ce235d453f8d..cfc32c0ba5fc1accb6623bf009e0e8312d575dec 100644
--- a/xfa/fwl/core/ifwl_picturebox.h
+++ b/xfa/fwl/core/ifwl_picturebox.h
@@ -12,7 +12,6 @@
 #include "xfa/fwl/core/ifwl_dataprovider.h"
 #include "xfa/fwl/core/ifwl_widget.h"
 
-#define FWL_CLASS_PictureBox L"FWL_PICTUREBOX"
 #define FWL_STYLEEXT_PTB_Left 0L << 0
 #define FWL_STYLEEXT_PTB_Center 1L << 0
 #define FWL_STYLEEXT_PTB_Right 2L << 0
@@ -49,10 +48,9 @@ class IFWL_PictureBox : public IFWL_Widget {
   ~IFWL_PictureBox() 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;
   FWL_Error Update() override;
   FWL_Error DrawWidget(CFX_Graphics* pGraphics,