Convert ARRAYSIZE_UNSAFE -> arraysize in base/.

R=thestig@chromium.org
BUG=423134

Review URL: https://codereview.chromium.org/656033009

Cr-Commit-Position: refs/heads/master@{#299835}
void PrintToStderr(const char* output) {
  ignore_result(HANDLE_EINTR(write(STDERR_FILENO, output, strlen(output))));
}

void PrintToStderr(const char* output) {
  ignore_result(HANDLE_EINTR(write(STDERR_FILENO, output, strlen(output))));
}
