A fix in the spirit of PR https://github.com/playframework/playframework/pull/1962, but fixes up a compilation issue that broke the build. The major difference with the API is that instead of passing in a WebDriver class, WebDriver instances are always required. However the default WebDriver instance is of clazz HTMLUNIT. Alternate ones can be passed in using WebDriverFactory(clazz) instead of just clazz as before.
Merge remote-tracking branch: upstream/master