Currently, requests to add extensions may arrive before we actually request extensions list in ExtensionServer.initExtensions(). One reason for that is chromium (InspectorExtensionsRegistry.getExtensionsAsync() is a no-op, we always send the extension list from the browser), another potential code path is remote front-end extensions using window.addExtension(). This may lead to extensions sending requests before extension subsystem is initialized (i.e. we install event listeners etc).
Thanks to email@example.com for investigating this.
Created attachment 164544 [details]
Committed r128892: <http://trac.webkit.org/changeset/128892>