Use virtual function to retrieve interface pointer

xfa/fxfa/app/xfa_fftextedit.cpp

Index: xfa/fxfa/app/xfa_fftextedit.cpp
diff --git a/xfa/fxfa/app/xfa_fftextedit.cpp b/xfa/fxfa/app/xfa_fftextedit.cpp
index 398cf87cd88ad0aaf10e23ecf05c1d6386294334..6df4507e2202e6b07a73f8b2adcf017fb94e4108 100644
--- a/xfa/fxfa/app/xfa_fftextedit.cpp
+++ b/xfa/fxfa/app/xfa_fftextedit.cpp
@@ -111,7 +111,7 @@ FX_BOOL CXFA_FFTextEdit::OnLButtonDown(uint32_t dwFlags,
   ms.m_dwFlags = dwFlags;
   ms.m_fx = fx;
   ms.m_fy = fy;
-  ms.m_pDstTarget = m_pNormalWidget->m_pIface;
+  ms.m_pDstTarget = m_pNormalWidget->GetWidget();
   FWLToClient(ms.m_fx, ms.m_fy);
   TranslateFWLMessage(&ms);
   return TRUE;
@@ -158,14 +158,14 @@ FX_BOOL CXFA_FFTextEdit::OnSetFocus(CXFA_FFWidget* pOldWidget) {
   }
   CXFA_FFWidget::OnSetFocus(pOldWidget);
   CFWL_MsgSetFocus ms;
-  ms.m_pDstTarget = m_pNormalWidget->m_pIface;
+  ms.m_pDstTarget = m_pNormalWidget->GetWidget();
   ms.m_pSrcTarget = nullptr;
   TranslateFWLMessage(&ms);
   return TRUE;
 }
 FX_BOOL CXFA_FFTextEdit::OnKillFocus(CXFA_FFWidget* pNewWidget) {
   CFWL_MsgKillFocus ms;
-  ms.m_pDstTarget = m_pNormalWidget->m_pIface;
+  ms.m_pDstTarget = m_pNormalWidget->GetWidget();
   ms.m_pSrcTarget = nullptr;
   TranslateFWLMessage(&ms);
   m_dwStatus &= ~XFA_WidgetStatus_Focused;