[ServiceWorker] Add WebDataSource argument to isControlledByServiceWorker() [1/3 blink]

In current implementation, while the new page is loading the request from the existing previous page may refer to the provisional dataSource in isControlledByServiceWorker().
But this is wrong.
We should pass WebDataSource to this method to avoid the ambiguity.

1/3 blink: https://codereview.chromium.org/634813002
2/3 chromium: https://codereview.chromium.org/629953003
3/3 blink: https://codereview.chromium.org/635693003

BUG=411151

Review URL: https://codereview.chromium.org/634813002

git-svn-id: svn://svn.chromium.org/blink/trunk@183375 bbb929c8-8fbe-4397-9dbb-9b2b20218538