Change IFWL_Widget to store a single delegate.

xfa/fwl/core/ifwl_formproxy.cpp

Index: xfa/fwl/core/ifwl_formproxy.cpp
diff --git a/xfa/fwl/core/ifwl_formproxy.cpp b/xfa/fwl/core/ifwl_formproxy.cpp
index dee8973bc7da10fbdb04ea1f338672bf7510e7c6..47178e7c6a66cd812920ace641f830abed736416 100644
--- a/xfa/fwl/core/ifwl_formproxy.cpp
+++ b/xfa/fwl/core/ifwl_formproxy.cpp
@@ -42,5 +42,5 @@ CFWL_FormProxyImpDelegate::CFWL_FormProxyImpDelegate(IFWL_FormProxy* pOwner)
     : m_pOwner(pOwner) {}
 
 void CFWL_FormProxyImpDelegate::OnProcessMessage(CFWL_Message* pMessage) {
-  m_pOwner->m_pOuter->GetCurrentDelegate()->OnProcessMessage(pMessage);
+  m_pOwner->m_pOuter->GetDelegate()->OnProcessMessage(pMessage);
 }