Add ishell@ to OWNERS.

TBR=danno@chromium.org

Review URL: https://codereview.chromium.org/32523002

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@17296 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

OWNERS

@@ -2,6 +2,7 @@ bmeurer@chromium.org
 danno@chromium.org
 dslomov@chromium.org
 hpayer@chromium.org
+ishell@chromium.org
 jkummerow@chromium.org
 machenbach@chromium.org
 mstarzinger@chromium.org