In auto-import:
  https://chromium-review.googlesource.com/c/561596/

And manual import:
  https://chromium-review.googlesource.com/c/561917/

The importer logged:

Waiting. 5680 seconds passed.
Adding test expectations lines to LayoutTests/TestExpectations.
All jobs finished.
No results for build Build(builder_name=u'android_blink_rel', build_number=2856)
Tests to rebaseline:
Lines to write to TestExpectations:
# ret> 1
# out> On branch update_wpt
# out> Your branch is ahead of 'origin/master' by 1 commit.
# out>   (use "git push" to publish your local commits)
# out> nothing to commit, working tree clean
step returned non-zero exit code: 1

This is because in TestImporter we have:

    if try_results and self.git_cl.has_failing_try_results(try_results):
        self.fetch_new_expectations_and_baselines()
        message = 'Update test expectations and baselines.'
        self.check_run(['git', 'commit', '-a', '-m', message])
        self._upload_patchset(message)

(An exception is raised in check_run if there's nothing to commit)

Commit/upload should only be done if there are changes.