Bug 914748 - openURI and openURIInFrame should not throw exceptions in the OPEN_NEWTAB case when they didn't create a new browser. r=felipe

--HG--
extra : rebase_source : d165be0f58bf138bed3ef59559b74b81d5ed2a57
Bug 914748 - Let openURL call openUILinkIn rather than browserDOMWindow.openURI, as the latter may do nothing and return null. r=felipe

--HG--
extra : rebase_source : ca103aae1589352bd5ee3d9deb8c23f2770d912e