https://crrev.com/c/992236 introduced base::data(), modeled after C++17's std::data() [1]. Due to the lack of a non-const std::basic_string::data() in C++14 base::data() contains a special case for mutable strings. This special case provides a similar functionality to base::string_as_array. Since base::data() is more widely applicable, it is the preferred solution and existing usages of  base::string_as_array should be replaced by std::data(std::string&).

[1] http://en.cppreference.com/w/cpp/iterator/data