We currently have a separate message channel for evals in front-end context invoked from extension tests. This has negative impact on tests stability, as the message delivery order is not guaranteed for two different ports -- the extension output interleaving with front-end output (i.e. from console.log()) is a common source of flakiness. The proposed fix is to expose extensionServer to test code, so we can re-use the existing port and make sure test output is well serialized WRT extension commands.
Created attachment 187580 [details] Patch
Committed r142485: <http://trac.webkit.org/changeset/142485>