Push API: pass ServiceWorkerRegistration for registration from document [switchover 3/6]
Push API: pass ServiceWorkerRegistration for registration from document [switchover 3/6]

Also delete obsolete permission request callback.

This patch has no dependencies.

This part 3 of a series of 6 patches. See https://crbug.com/440076 for the plan to land them.

BUG=389194, 440076

Review URL: https://codereview.chromium.org/786013002

git-svn-id: bf5cd6ccde378db821296732a091cfbcf5285fbd@186777 bbb929c8-8fbe-4397-9dbb-9b2b20218538

primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs