Bug 1577881 - Watch out for dead windows in getAllWindowDebuggees, r=ochameau.

Differential Revision: https://phabricator.services.mozilla.com/D45114

--HG--
extra : moz-landing-system : lando

devtools/server/actors/utils/event-loop.js

@@ -5,6 +5,7 @@
 "use strict";
 
 const xpcInspector = require("xpcInspector");
+const { Cu } = require("chrome");
 
 /**
  * Manages pushing event loops and automatically pops and exits them in the
@@ -131,7 +132,7 @@ EventLoop.prototype = {
         })
         // Ignore iframes as they will be paused automatically when pausing their
         // owner top level document
-        .filter(window => window.top === window)
+        .filter(window => !Cu.isDeadWrapper(window) && window.top === window)
     );
   },