Change IFWL_Widget to store a single delegate.

xfa/fxfa/app/xfa_fftextedit.h

Index: xfa/fxfa/app/xfa_fftextedit.h
diff --git a/xfa/fxfa/app/xfa_fftextedit.h b/xfa/fxfa/app/xfa_fftextedit.h
index 048008d700a1e451821302898e90ed4d1d52153f..db98641d7a6422d3ddc8623f5f070b353754dc6a 100644
--- a/xfa/fxfa/app/xfa_fftextedit.h
+++ b/xfa/fxfa/app/xfa_fftextedit.h
@@ -42,10 +42,6 @@ class CXFA_FFTextEdit : public CXFA_FFField {
                           std::vector<CFX_ByteString>& sSuggest) override;
   FX_BOOL ReplaceSpellCheckWord(CFX_PointF pointf,
                                 const CFX_ByteStringC& bsReplace) override;
-  void OnProcessMessage(CFWL_Message* pMessage) override;
-  void OnProcessEvent(CFWL_Event* pEvent) override;
-  void OnDrawWidget(CFX_Graphics* pGraphics,
-                    const CFX_Matrix* pMatrix = nullptr) override;
 
   void OnTextChanged(IFWL_Widget* pWidget,
                      const CFX_WideString& wsChanged,
@@ -60,8 +56,6 @@ class CXFA_FFTextEdit : public CXFA_FFField {
 
   uint32_t GetAlignment();
   void ValidateNumberField(const CFX_WideString& wsText);
-
-  IFWL_WidgetDelegate* m_pOldDelegate;
 };
 
 class CXFA_FFNumericEdit : public CXFA_FFTextEdit {
@@ -72,7 +66,6 @@ class CXFA_FFNumericEdit : public CXFA_FFTextEdit {
   // CXFA_FFTextEdit
   FX_BOOL LoadWidget() override;
   void UpdateWidgetProperty() override;
-  void OnProcessEvent(CFWL_Event* pEvent) override;
 
  public:
   FX_BOOL OnValidate(IFWL_Widget* pWidget, CFX_WideString& wsText);
@@ -122,7 +115,6 @@ class CXFA_FFDateTimeEdit : public CXFA_FFTextEdit {
   FX_BOOL SelectAll() override;
   FX_BOOL Delete() override;
   FX_BOOL DeSelect() override;
-  void OnProcessEvent(CFWL_Event* pEvent) override;
 
   void OnSelectChanged(IFWL_Widget* pWidget,
                        int32_t iYear,