Make printing paint-dev's responsibility

Missed this update before committing the original patch.

TBR=chrishtr@chromium.org

Change-Id: I4fcda12146e7920615e4939785c39b8f220bc005
Reviewed-on: https://chromium-review.googlesource.com/1204671Reviewed-by: Stephen Chenney <schenney@chromium.org>
Reviewed-by: Chris Harrelson <chrishtr@chromium.org>
Commit-Queue: Chris Harrelson <chrishtr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#594521}

third_party/WebKit/LayoutTests/printing/OWNERS

-# TEAM: layout-dev@chromium.org
-# COMPONENT: Blink>Layout
+# TEAM: paint-dev@chromium.org
+# COMPONENT: Blink>Paint