Change IFWL_Widget to store a single delegate.

xfa/fwl/core/ifwl_datetimeedit.cpp

Index: xfa/fwl/core/ifwl_datetimeedit.cpp
diff --git a/xfa/fwl/core/ifwl_datetimeedit.cpp b/xfa/fwl/core/ifwl_datetimeedit.cpp
index 1c0baae32d2b4a8c8bf9000e84fe6ad3762b4cb8..c9fd7b7f60ef985d1785c9928d542cb64c6ac296 100644
--- a/xfa/fwl/core/ifwl_datetimeedit.cpp
+++ b/xfa/fwl/core/ifwl_datetimeedit.cpp
@@ -31,7 +31,7 @@ void CFWL_DateTimeEditImpDelegate::OnProcessMessage(CFWL_Message* pMessage) {
   if (dwHashCode == CFWL_MessageType::SetFocus ||
       dwHashCode == CFWL_MessageType::KillFocus) {
     IFWL_Widget* pOuter = m_pOwner->GetOuter();
-    pOuter->GetCurrentDelegate()->OnProcessMessage(pMessage);
+    pOuter->GetDelegate()->OnProcessMessage(pMessage);
   }
 }