Add glenrob to web_applications OWNERS

Change-Id: Ie4499ae0d7c26bffbe1b5cb620ae60c1a8aba2c4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2306501
Auto-Submit: Alan Cutter <alancutter@chromium.org>
Reviewed-by: Glen Robertson <glenrob@chromium.org>
Commit-Queue: Glen Robertson <glenrob@chromium.org>
Cr-Commit-Position: refs/heads/master@{#789844}

chrome/browser/web_applications/OWNERS

@@ -5,6 +5,7 @@ cmp@chromium.org
 dmurph@chromium.org
 dominickn@chromium.org
 ericwilligers@chromium.org
+glenrob@chromium.org
 loyso@chromium.org
 mgiuca@chromium.org
 nigeltao@chromium.org