Add haraken@ to public/OWNERS

I've reviewed a lot of patches that need changes to public/ mostly in the context of Onion Soup.
Also I hope this will be helpful to increase active reviewers in APAC time
who can review trivial changes to public/.

BUG=
NOTRY=true

Review-Url: https://codereview.chromium.org/2389663002
Cr-Commit-Position: refs/heads/master@{#422678}

third_party/WebKit/public/OWNERS

@@ -5,6 +5,7 @@ dglazkov@chromium.org
 dstockwell@chromium.org
 esprehn@chromium.org
 foolip@chromium.org
+haraken@chromium.org
 japhet@chromium.org
 jochen@chromium.org
 kinuko@chromium.org