Get rid of NULLs in xfa/

xfa/fwl/basewidget/fwl_datetimepickerimp.h

Index: xfa/fwl/basewidget/fwl_datetimepickerimp.h
diff --git a/xfa/fwl/basewidget/fwl_datetimepickerimp.h b/xfa/fwl/basewidget/fwl_datetimepickerimp.h
index 8490324d9dd0e0054384768aa982054da007440a..dc9036a6fcc30915097988494f945ea9bc6556cf 100644
--- a/xfa/fwl/basewidget/fwl_datetimepickerimp.h
+++ b/xfa/fwl/basewidget/fwl_datetimepickerimp.h
@@ -175,7 +175,7 @@ class CFWL_DateTimePickerImp : public CFWL_WidgetImp {
   FWL_Error DisForm_GetWidgetRect(CFX_RectF& rect, FX_BOOL bAutoSize = FALSE);
   FWL_Error DisForm_GetBBox(CFX_RectF& rect);
   FWL_Error DisForm_DrawWidget(CFX_Graphics* pGraphics,
-                               const CFX_Matrix* pMatrix = NULL);
+                               const CFX_Matrix* pMatrix = nullptr);
 
  protected:
   CFX_RectF m_rtBtn;
@@ -219,7 +219,7 @@ class CFWL_DateTimePickerImpDelegate : public CFWL_WidgetImpDelegate {
   CFWL_DateTimePickerImpDelegate(CFWL_DateTimePickerImp* pOwner);
   void OnProcessMessage(CFWL_Message* pMessage) override;
   void OnDrawWidget(CFX_Graphics* pGraphics,
-                    const CFX_Matrix* pMatrix = NULL) override;
+                    const CFX_Matrix* pMatrix = nullptr) override;
 
  protected:
   void OnFocusChanged(CFWL_Message* pMsg, FX_BOOL bSet = TRUE);