Cleanup unused methods and return values in FWL code.

xfa/fwl/theme/cfwl_listboxtp.cpp

Index: xfa/fwl/theme/cfwl_listboxtp.cpp
diff --git a/xfa/fwl/theme/cfwl_listboxtp.cpp b/xfa/fwl/theme/cfwl_listboxtp.cpp
index 69fc0719f85a56ef2ee91f5d2e9bc7dc0314df47..304c3a8397b620310733d24876e98fad31eb9847 100644
--- a/xfa/fwl/theme/cfwl_listboxtp.cpp
+++ b/xfa/fwl/theme/cfwl_listboxtp.cpp
@@ -20,9 +20,10 @@ bool CFWL_ListBoxTP::IsValidWidget(IFWL_Widget* pWidget) {
   return pWidget && pWidget->GetClassID() == FWL_Type::ListBox;
 }
 
-FX_BOOL CFWL_ListBoxTP::DrawBackground(CFWL_ThemeBackground* pParams) {
+void CFWL_ListBoxTP::DrawBackground(CFWL_ThemeBackground* pParams) {
   if (!pParams)
-    return FALSE;
+    return;
+
   switch (pParams->m_iPart) {
     case CFWL_Part::Border: {
       DrawBorder(pParams->m_pGraphics, &pParams->m_rtPart, &pParams->m_matrix);
@@ -62,18 +63,21 @@ FX_BOOL CFWL_ListBoxTP::DrawBackground(CFWL_ThemeBackground* pParams) {
       FillSoildRect(pParams->m_pGraphics, color, &pParams->m_rtPart,
                     &pParams->m_matrix);
     }
-    default: {}
+    default:
+      break;
   }
-  return TRUE;
 }
-FWL_Error CFWL_ListBoxTP::Initialize() {
+
+void CFWL_ListBoxTP::Initialize() {
   InitTTO();
-  return CFWL_WidgetTP::Initialize();
+  CFWL_WidgetTP::Initialize();
 }
-FWL_Error CFWL_ListBoxTP::Finalize() {
+
+void CFWL_ListBoxTP::Finalize() {
   FinalizeTTO();
-  return CFWL_WidgetTP::Finalize();
+  CFWL_WidgetTP::Finalize();
 }
+
 void CFWL_ListBoxTP::DrawListBoxItem(CFX_Graphics* pGraphics,
                                      uint32_t dwStates,
                                      const CFX_RectF* prtItem,
@@ -96,9 +100,6 @@ void CFWL_ListBoxTP::DrawListBoxItem(CFX_Graphics* pGraphics,
     pGraphics->FillPath(&path, FXFILL_WINDING, pMatrix);
     pGraphics->RestoreGraphState();
   }
-  if (dwStates & CFWL_PartState_Focused) {
-    if (pData) {
-      DrawFocus(pGraphics, (CFX_RectF*)pData, pMatrix);
-    }
-  }
+  if (dwStates & CFWL_PartState_Focused && pData)
+    DrawFocus(pGraphics, (CFX_RectF*)pData, pMatrix);
 }