When `Target.setDiscoverTargets` is called, one `Target.targetCreated` event
should be sent per already opened tab.
Differential Revision: https://phabricator.services.mozilla.com/D25558
--HG--
extra : moz-landing-system : lando
Empty methods that are necessary to make puppeteer.connect to pass without throwing.
Depends on D22692
Differential Revision: https://phabricator.services.mozilla.com/D22693
--HG--
rename : remote/domains/ParentProcessDomains.jsm => remote/domains/parent/Target.jsm
extra : moz-landing-system : lando