Convert FWL_ERR into an enum class.

xfa/fwl/basewidget/fwl_pushbuttonimp.h

Index: xfa/fwl/basewidget/fwl_pushbuttonimp.h
diff --git a/xfa/fwl/basewidget/fwl_pushbuttonimp.h b/xfa/fwl/basewidget/fwl_pushbuttonimp.h
index be6941249cbdff4af200918d96058801bf54dad1..cbe11e915f24888c1ba5ea6ac4e2f881bb2571a6 100644
--- a/xfa/fwl/basewidget/fwl_pushbuttonimp.h
+++ b/xfa/fwl/basewidget/fwl_pushbuttonimp.h
@@ -19,15 +19,15 @@ class CFWL_PushButtonImp : public CFWL_WidgetImp {
   CFWL_PushButtonImp(const CFWL_WidgetImpProperties& properties,
                      IFWL_Widget* pOuter);
   virtual ~CFWL_PushButtonImp();
-  virtual FWL_ERR GetClassName(CFX_WideString& wsClass) const;
+  virtual FWL_Error GetClassName(CFX_WideString& wsClass) const;
   virtual uint32_t GetClassID() const;
-  virtual FWL_ERR Initialize();
-  virtual FWL_ERR Finalize();
-  virtual FWL_ERR GetWidgetRect(CFX_RectF& rect, FX_BOOL bAutoSize = FALSE);
-  virtual FWL_ERR SetStates(uint32_t dwStates, FX_BOOL bSet = TRUE);
-  virtual FWL_ERR Update();
-  virtual FWL_ERR DrawWidget(CFX_Graphics* pGraphics,
-                             const CFX_Matrix* pMatrix = NULL);
+  virtual FWL_Error Initialize();
+  virtual FWL_Error Finalize();
+  virtual FWL_Error GetWidgetRect(CFX_RectF& rect, FX_BOOL bAutoSize = FALSE);
+  virtual FWL_Error SetStates(uint32_t dwStates, FX_BOOL bSet = TRUE);
+  virtual FWL_Error Update();
+  virtual FWL_Error DrawWidget(CFX_Graphics* pGraphics,
+                               const CFX_Matrix* pMatrix = NULL);
 
  protected:
   void DrawBkground(CFX_Graphics* pGraphics,
@@ -50,9 +50,9 @@ class CFWL_PushButtonImpDelegate : public CFWL_WidgetImpDelegate {
  public:
   CFWL_PushButtonImpDelegate(CFWL_PushButtonImp* pOwner);
   int32_t OnProcessMessage(CFWL_Message* pMessage) override;
-  FWL_ERR OnProcessEvent(CFWL_Event* pEvent) override;
-  FWL_ERR OnDrawWidget(CFX_Graphics* pGraphics,
-                       const CFX_Matrix* pMatrix = NULL) override;
+  FWL_Error OnProcessEvent(CFWL_Event* pEvent) override;
+  FWL_Error OnDrawWidget(CFX_Graphics* pGraphics,
+                         const CFX_Matrix* pMatrix = NULL) override;
 
  protected:
   void OnFocusChanged(CFWL_Message* pMsg, FX_BOOL bSet = TRUE);