Get rid of NULLs in xfa/

xfa/fwl/core/cfwl_widgetmgr.h

Index: xfa/fwl/core/cfwl_widgetmgr.h
diff --git a/xfa/fwl/core/cfwl_widgetmgr.h b/xfa/fwl/core/cfwl_widgetmgr.h
index 957f6dc42819ab19cd373926ec46bb244ca27b5b..820375e7772f5c0e72adf00e4bb264f39b66a21a 100644
--- a/xfa/fwl/core/cfwl_widgetmgr.h
+++ b/xfa/fwl/core/cfwl_widgetmgr.h
@@ -75,7 +75,8 @@ class CFWL_WidgetMgr {
   IFWL_Widget* GetSystemFormWidget(IFWL_Widget* pWidget) const;
 
   FX_BOOL SetWidgetIndex(IFWL_Widget* pWidget, int32_t nIndex);
-  FWL_Error RepaintWidget(IFWL_Widget* pWidget, const CFX_RectF* pRect = NULL);
+  FWL_Error RepaintWidget(IFWL_Widget* pWidget,
+                          const CFX_RectF* pRect = nullptr);
 
   void AddWidget(IFWL_Widget* pWidget);
   void InsertWidget(IFWL_Widget* pParent,
@@ -112,7 +113,7 @@ class CFWL_WidgetMgr {
   int32_t TravelWidgetMgr(CFWL_WidgetMgrItem* pParent,
                           int32_t* pIndex,
                           CFWL_WidgetMgrItem* pItem,
-                          IFWL_Widget** pWidget = NULL);
+                          IFWL_Widget** pWidget = nullptr);
   FX_BOOL IsAbleNative(IFWL_Widget* pWidget) const;
 
   uint32_t m_dwCapability;