DevTools: bail out presubmit early if error after node.js or formatting checks

If there's a formatting error, you need to commit the formatting changes
and then re-run "git cl upload" so we just bail out of presubmit checks early
to save people time.

BUG=none

Review-Url: https://codereview.chromium.org/2538003002
Cr-Commit-Position: refs/heads/master@{#435736}
2 files changed