https://w3c.github.io/webdriver/webdriver-spec.html#dfn-validate-capabilities "4. If deserialized is not null, set a property on result with name name and value deserialized." We are adding it, causing a failure when matching capabilities.
Created attachment 326202 [details] Patch
Comment on attachment 326202 [details] Patch r=me
Committed r224667: <https://trac.webkit.org/changeset/224667>
<rdar://problem/35562186>