Use the compatibility mode to include Firefox/<version> with WebappRuntime/<version>.
--HG--
extra : rebase_source : 3e8a5bbeb50ef3cca68c2a8bc618ded968449039
Import Webapps.jsm to initialize DOMApplicationRegistry, which handles Webapps:GetSelf, etc. messages.
--HG--
extra : rebase_source : 429c9c48e54e39ff0c403d926c5ac35c49b28c3f