Add new owners to chrome/browser/chromeos/drive/.

Added folks who are familiar with the code.

TEST=None
BUG=None

Review URL: https://codereview.chromium.org/672423002

Cr-Commit-Position: refs/heads/master@{#301033}

chrome/browser/chromeos/drive/OWNERS

 hashimoto@chromium.org
 hidehiko@chromium.org
+hirono@chromium.org
 kinaba@chromium.org
+mtomasz@chromium.org
 satorux@chromium.org
 yoshiki@chromium.org