Standalone GN build.

core/fxcrt/fx_basic_wstring.cpp

Index: core/fxcrt/fx_basic_wstring.cpp
diff --git a/core/fxcrt/fx_basic_wstring.cpp b/core/fxcrt/fx_basic_wstring.cpp
index 069b9fa42d43ac1c5b506682ddc439ab406e76cf..1e8f1f32322168881e864a40aaa1ef32540f050b 100644
--- a/core/fxcrt/fx_basic_wstring.cpp
+++ b/core/fxcrt/fx_basic_wstring.cpp
@@ -579,6 +579,10 @@ void CFX_WideString::FormatV(const FX_WCHAR* pFormat, va_list argList) {
   va_end(argListSave);
 }
 
+const FX_WCHAR* CFX_WideString::c_str() const {
+  return m_pData ? m_pData->m_String : L"";
+}
+
 void CFX_WideString::Format(const FX_WCHAR* pFormat, ...) {
   va_list argList;
   va_start(argList, pFormat);