Headless: add some PST content/ owners to headless owners for faster …

…reviews.

Change-Id: I422b4fb9d65ab231e9736a890d292d7e2889c270
Reviewed-on: https://chromium-review.googlesource.com/1077084
Reviewed-by: Pavel Feldman <pfeldman@chromium.org>
Cr-Commit-Position: refs/heads/master@{#562567}

headless/OWNERS

@@ -2,6 +2,10 @@ skyostil@chromium.org
 alexclarke@chromium.org
 eseckler@chromium.org
 
+# PST
+dgozman@chromium.org
+pfeldman@chromium.org
+
 # Emeritus:
 altimin@chromium.org
 dvallet@chromium.org