Fix invalid cast in CXFA_FFNotify::OnLayoutItemRemoving().

xfa/src/fxfa/src/app/xfa_ffnotify.cpp

Index: xfa/src/fxfa/src/app/xfa_ffnotify.cpp
diff --git a/xfa/src/fxfa/src/app/xfa_ffnotify.cpp b/xfa/src/fxfa/src/app/xfa_ffnotify.cpp
index 24b72f8e23b77f4f8aa3439321c98944d448183a..aff2b40d3a78cee4bbe62ce5556e8a8a20d3c410 100644
--- a/xfa/src/fxfa/src/app/xfa_ffnotify.cpp
+++ b/xfa/src/fxfa/src/app/xfa_ffnotify.cpp
@@ -605,7 +605,8 @@ void CXFA_FFNotify::OnLayoutItemRemoving(CXFA_FFDocView* pDocView,
                                          CXFA_LayoutItem* pSender,
                                          void* pParam,
                                          void* pParam2) {
-  CXFA_FFWidget* pWidget = (CXFA_FFWidget*)pSender;
+  CXFA_FFWidget* pWidget = static_cast<CXFA_FFWidget*>(
+      reinterpret_cast<CXFA_ContentLayoutItemImpl*>(pSender));
   pDocView->DeleteLayoutItem(pWidget);
   if (pDocView->GetLayoutStatus() < XFA_DOCVIEW_LAYOUTSTATUS_End) {
     return;