Change IFWL_Widget to store a single delegate.

xfa/fxfa/app/xfa_fffield.h

Index: xfa/fxfa/app/xfa_fffield.h
diff --git a/xfa/fxfa/app/xfa_fffield.h b/xfa/fxfa/app/xfa_fffield.h
index 8481018189b79c732617687a08c26137dac5db1b..026f113a96114cdf94b6db8aec879e7849f32ece 100644
--- a/xfa/fxfa/app/xfa_fffield.h
+++ b/xfa/fxfa/app/xfa_fffield.h
@@ -8,14 +8,13 @@
 #define XFA_FXFA_APP_XFA_FFFIELD_H_
 
 #include "xfa/fwl/core/cfwl_widget.h"
-#include "xfa/fwl/core/ifwl_widgetdelegate.h"
 #include "xfa/fxfa/xfa_ffpageview.h"
 #include "xfa/fxfa/xfa_ffwidget.h"
 
 #define XFA_MINUI_HEIGHT 4.32f
 #define XFA_DEFAULTUI_HEIGHT 2.0f
 
-class CXFA_FFField : public CXFA_FFWidget, public IFWL_WidgetDelegate {
+class CXFA_FFField : public CXFA_FFWidget {
  public:
   CXFA_FFField(CXFA_FFPageView* pPageView, CXFA_WidgetAcc* pDataAcc);
   ~CXFA_FFField() override;
@@ -53,28 +52,24 @@ class CXFA_FFField : public CXFA_FFWidget, public IFWL_WidgetDelegate {
   FWL_WidgetHit OnHitTest(FX_FLOAT fx, FX_FLOAT fy) override;
   FX_BOOL OnSetCursor(FX_FLOAT fx, FX_FLOAT fy) override;
 
-  // IFWL_WidgetDelegate
-  void OnProcessMessage(CFWL_Message* pMessage) override;
-  void OnProcessEvent(CFWL_Event* pEvent) override;
-  void OnDrawWidget(CFX_Graphics* pGraphics,
-                    const CFX_Matrix* pMatrix = nullptr) override;
-
   void UpdateFWL();
   uint32_t UpdateUIProperty();
 
+  CFWL_Widget* GetNormalWidget() { return m_pNormalWidget; }
+  FX_BOOL ProcessCommittedData();
+
  protected:
   FX_BOOL PtInActiveRect(FX_FLOAT fx, FX_FLOAT fy) override;
 
   virtual void SetFWLRect();
   void SetFWLThemeProvider();
-  CFWL_Widget* GetNormalWidget() { return m_pNormalWidget; }
   void FWLToClient(FX_FLOAT& fx, FX_FLOAT& fy);
   void LayoutCaption();
   void RenderCaption(CFX_Graphics* pGS, CFX_Matrix* pMatrix = nullptr);
 
   int32_t CalculateOverride();
   int32_t CalculateWidgetAcc(CXFA_WidgetAcc* pAcc);
-  FX_BOOL ProcessCommittedData();
+
   virtual FX_BOOL CommitData();
   virtual FX_BOOL IsDataChanged();
   void DrawHighlight(CFX_Graphics* pGS,