Convert FWL_ERR into an enum class.

xfa/fwl/core/ifwl_tooltiptarget.h

Index: xfa/fwl/core/ifwl_tooltiptarget.h
diff --git a/xfa/fwl/core/ifwl_tooltiptarget.h b/xfa/fwl/core/ifwl_tooltiptarget.h
index 0b364f2754f7355737d6797d38162e8c78017180..7489e73efd0a5d86b798c8aa3d199a7da083a126 100644
--- a/xfa/fwl/core/ifwl_tooltiptarget.h
+++ b/xfa/fwl/core/ifwl_tooltiptarget.h
@@ -20,13 +20,15 @@ class IFWL_ToolTipTarget {
   virtual ~IFWL_ToolTipTarget() {}
   virtual IFWL_Widget* GetWidget() = 0;
   virtual FX_BOOL IsShowed() = 0;
-  virtual FWL_ERR DrawToolTip(CFX_Graphics* pGraphics,
-                              const CFX_Matrix* pMatrix,
-                              IFWL_Widget* pToolTip) = 0;
+  virtual FWL_Error DrawToolTip(CFX_Graphics* pGraphics,
+                                const CFX_Matrix* pMatrix,
+                                IFWL_Widget* pToolTip) = 0;
   virtual FX_BOOL UseDefaultTheme() = 0;
-  virtual FWL_ERR GetCaption(CFX_WideString& wsCaption) = 0;
-  virtual FWL_ERR GetToolTipSize(CFX_SizeF& sz) = 0;
-  virtual FWL_ERR GetToolTipPos(CFX_PointF& pt) { return FWL_ERR_Indefinite; }
+  virtual FWL_Error GetCaption(CFX_WideString& wsCaption) = 0;
+  virtual FWL_Error GetToolTipSize(CFX_SizeF& sz) = 0;
+  virtual FWL_Error GetToolTipPos(CFX_PointF& pt) {
+    return FWL_Error::Indefinite;
+  }
 };
 
 #endif  // XFA_FWL_CORE_IFWL_TOOLTIPTARGET_H_