Make CFWL_WidgetMgr{Delegate} inherit from IFWL_WidgetMgr{Delegate}.

xfa/src/fwl/src/core/fwl_appimp.cpp

Index: xfa/src/fwl/src/core/fwl_appimp.cpp
diff --git a/xfa/src/fwl/src/core/fwl_appimp.cpp b/xfa/src/fwl/src/core/fwl_appimp.cpp
index d9d37e2f9e2b03e70b1b2f7cb3c04ee1fdb92c09..948001c21dc35983725aaba5690bc58cdc2dc616 100644
--- a/xfa/src/fwl/src/core/fwl_appimp.cpp
+++ b/xfa/src/fwl/src/core/fwl_appimp.cpp
@@ -41,10 +41,8 @@ FWL_ERR CFWL_AppImp::Initialize() {
   return FWL_ERR_Succeeded;
 }
 FWL_ERR CFWL_AppImp::Finalize() {
-  if (m_pWidgetMgr) {
-    delete m_pWidgetMgr;
-    m_pWidgetMgr = NULL;
-  }
+  delete m_pWidgetMgr;
+  m_pWidgetMgr = NULL;
   return FWL_ERR_Succeeded;
 }
 IFWL_AdapterNative* CFWL_AppImp::GetAdapterNative() {
@@ -54,7 +52,7 @@ IFWL_AdapterWidgetMgr* FWL_GetAdapterWidgetMgr() {
   return ((CFWL_WidgetMgr*)FWL_GetWidgetMgr())->GetAdapterWidgetMgr();
 }
 IFWL_WidgetMgr* CFWL_AppImp::GetWidgetMgr() {
-  return (IFWL_WidgetMgr*)m_pWidgetMgr;
+  return m_pWidgetMgr;
 }
 FWL_ERR CFWL_AppImp::SetThemeProvider(IFWL_ThemeProvider* pThemeProvider) {
   m_pThemeProvider = pThemeProvider;