// Utility to register JSWindowActors var gZenActorsManager = { _actors: new Set(), addJSWindowActor(...args) { if (this._actors.has(args[0])) { // Actor already registered, nothing to do return; } try { ChromeUtils.registerWindowActor(...args); this._actors.add(args[0]); } catch (e) { console.warn(`Failed to register JSWindowActor: ${e}`); } }, }