Add some owners for chrome/browser/io_thread*.

NOTRY=true

Review URL: https://codereview.chromium.org/439883002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@287498 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/OWNERS

@@ -15,6 +15,11 @@ per-file chrome_elf_init_*=robertshield@chromium.org
 
 per-file enumerate_modules_model*=finnur@chromium.org
 
+per-file io_thread*=cbentzel@chromium.org
+per-file io_thread*=mmenke@chromium.org
+per-file io_thread*=rsleevi@chromium.org
+per-file io_thread*=willchan@chromium.org
+
 per-file shell_integration_win*=gab@chromium.org
 per-file shell_integration_win*=grt@chromium.org
 per-file shell_integration_linux*=erg@chromium.org