Code review comment for lp:~elopio/webbrowser-app/test_add_bookmark

Thanks for improving the test coverage!
With the re-design of the browser app happening now, the entire activity view is going away, so I’m kind of reluctant to merging this now as it will have to be entirely rewritten very soon.
If there are general improvements that can be extracted from this branch and applied to the existing tests, I’d gladly take them in though.