Add the "options_ui" extension manifest field.

extensions/common/api/_manifest_features.json

Index: extensions/common/api/_manifest_features.json
diff --git a/extensions/common/api/_manifest_features.json b/extensions/common/api/_manifest_features.json
index 271eea78558a916f5462fe0caf4de2e1e48bda44..dfd0e3711a0270cd18679014285849b93f57aca8 100644
--- a/extensions/common/api/_manifest_features.json
+++ b/extensions/common/api/_manifest_features.json
@@ -95,6 +95,10 @@
       "extension", "legacy_packaged_app", "hosted_app", "platform_app"
     ]
   },
+  "options_ui": {
+    "channel": "trunk",
+    "extension_types": ["extension"]

[Yoyo Zhou, 2014/08/29 23:06:27]

Do we want legacy_packaged_app too? Those also show up in chrome://extensions.

[not at google - send to devlin, 2014/08/29 23:26:42]

I was thinking no, since we don't want to give legacy packaged apps any new
features. However now that I think about it... perhaps this should be an
exception. It's a bit mean to potentially break legacy packaged apps without the
ability for them to opt out. The deprecation process can happen elsewhere.

[ericzeng, 2014/09/02 18:23:37]

Adding legacy packaged apps to the list.

+  },
   "sandbox": {
     "channel": "stable",
     "extension_types": [