../../buildtools/third_party/libc++/trunk/include/map:1207:17: error: no matching function for call to object of type 'const l10n_util::StringComparator<std::__1::basic_string<base::char16, base::string16_char_traits> >'
            if (__tree_.value_comp().key_comp()(__k, __nd->__value_.__cc.first))
                ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../../buildtools/third_party/libc++/trunk/include/map:1376:36: note: in instantiation of member function 'std::__1::map<std::__1::basic_string<base::char16, base::string16_char_traits>, std::__1::pair<std::__1::basic_string<char>, std::__1::basic_string<base::char16, base::string16_char_traits> >, l10n_util::StringComparator<std::__1::basic_string<base::char16, base::string16_char_traits> >, std::__1::allocator<std::__1::pair<const std::__1::basic_string<base::char16, base::string16_char_traits>, std::__1::pair<std::__1::basic_string<char>, std::__1::basic_string<base::char16, base::string16_char_traits> > > > >::__find_equal_key' requested here
    __node_base_pointer& __child = __find_equal_key(__parent, __k);
                                   ^
../../chrome/browser/extensions/api/language_settings_private/language_settings_private_api.cc:72:17: note: in instantiation of member function 'std::__1::map<std::__1::basic_string<base::char16, base::string16_char_traits>, std::__1::pair<std::__1::basic_string<char>, std::__1::basic_string<base::char16, base::string16_char_traits> >, l10n_util::StringComparator<std::__1::basic_string<base::char16, base::string16_char_traits> >, std::__1::allocator<std::__1::pair<const std::__1::basic_string<base::char16, base::string16_char_traits>, std::__1::pair<std::__1::basic_string<char>, std::__1::basic_string<base::char16, base::string16_char_traits> > > > >::operator[]' requested here
    language_map[display_name] = std::make_pair(code, native_display_name);
                ^
../../ui/base/l10n/l10n_util_collator.h:111:62: note: candidate function not viable: 'this' argument has type 'const l10n_util::StringComparator<std::__1::basic_string<base::char16, base::string16_char_traits> >', but method is not marked const
UI_BASE_EXPORT inline bool StringComparator<base::string16>::operator()(
                                                             ^