Merge "libbase: fix the way to find temp dir."

static std::string GetSystemTempDir() {

#if defined(__ANDROID__)

  return "/data/local/tmp";

  const char* tmpdir = "/data/local/tmp";

  if (access(tmpdir, R_OK | W_OK | X_OK) == 0) {

    return tmpdir;

  }

  // Tests running in app context can't access /data/local/tmp,

  // so try current directory if /data/local/tmp is not accessible.

  return ".";

#elif defined(_WIN32)

  char tmp_dir[MAX_PATH];

  DWORD result = GetTempPathA(sizeof(tmp_dir), tmp_dir);