Add mlamouri, beccahughes, and stemiel as owners for media_history* files.

Bug: 997813
Change-Id: Iaaa4aa2527d9a0f8e76cef84e17b0f1273f045ad
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1884365
Commit-Queue: Evan Liu <evliu@google.com>
Reviewed-by: Dale Curtis <dalecurtis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#710446}

chrome/browser/media/history/OWNERS

+# TEAM: media-dev@chromium.org
+# COMPONENT: Internals>Media>History
+
+evliu@google.org
+beccahughes@chromium.org
+steimel@chromium.org