Remove FWL globals.

xfa/fwl/core/cfwl_checkbox.h

Index: xfa/fwl/core/cfwl_checkbox.h
diff --git a/xfa/fwl/core/cfwl_checkbox.h b/xfa/fwl/core/cfwl_checkbox.h
index 9daab331500df8598293423680a61589ade33c3c..e17e6b5ef74db90baf3b2665a9ce743afec0d5c3 100644
--- a/xfa/fwl/core/cfwl_checkbox.h
+++ b/xfa/fwl/core/cfwl_checkbox.h
@@ -12,13 +12,14 @@
 
 class CFWL_CheckBox : public CFWL_Widget {
  public:
-  CFWL_CheckBox();
+  CFWL_CheckBox(const IFWL_App*);
   ~CFWL_CheckBox() override;
 
   IFWL_CheckBox* GetWidget() override;
   const IFWL_CheckBox* GetWidget() const override;
 
-  FWL_Error Initialize(const CFWL_WidgetProperties* pProperties = nullptr);
+  void Initialize(const CFWL_WidgetProperties* pProperties);
+
   FWL_Error SetCaption(const CFX_WideStringC& wsCaption);
   FWL_Error SetBoxSize(FX_FLOAT fHeight);
   int32_t GetCheckState();