Method set_write_fd

tests/gtest/gtest-all.cc:8021–8021

  void set_read_fd(int fd) { read_fd_ = fd; }
  int write_fd() const { return write_fd_; }
  void set_write_fd(int fd) { write_fd_ = fd; }

  // Called in the parent process only. Reads the result code of the death
  // test child process via a pipe, interprets it to set the outcome_