If a WebKit app injects a script into a webpage by calling JSEvaluateScript, the script doesn't appear in the Inspector's Scripts panel.
Turns out this only happens when no sourceURL parameter is passed to JSEvaluateScript.
Closing as invalid, as this bug pertains to the old inspector UI and/or its tests. Please file a new bug (https://www.webkit.org/new-inspector-bug) if the bug/feature/issue is still relevant to WebKit trunk.