Tests that browser.Target.setAutoAttach() executes script on load for window.open'ed pages.
Opened popup window
Attached to the popup window, waitingForDebugger=true
Resumed popup window
result: 42
Tests that browser.Target.setAutoAttach() executes script on load for window.open'ed pages.
Opened popup window
Attached to the popup window, waitingForDebugger=true
Resumed popup window
result: 42