devserver: Tests for CherryPy zero-port extensions.

This adds both unit tests, as well as extending integration tests, to
ensure that our CherryPy extensions module (cherrypy_ext) works as
intended.

BUG=chromium:322436
TEST=Unit + integration tests pass.

Change-Id: I93221d11d855cd4d78d39e34e587b5b24e9eb4d1
Reviewed-on: https://chromium-review.googlesource.com/186848
Tested-by: Gilad Arnold <garnold@chromium.org>
Reviewed-by: Chris Sosa <sosa@chromium.org>
Commit-Queue: Gilad Arnold <garnold@chromium.org>
2 files changed