Stop passing const-reference of SWRegistration in all GetRegistrationsCallbacks.

BUG=616502

Committed: https://crrev.com/36986071183bdb219186aa9f63f9ee4b162d91b9
Review-Url: https://codereview.chromium.org/2181553003
Cr-Original-Commit-Position: refs/heads/master@{#407487}
Cr-Commit-Position: refs/heads/master@{#407761}
36 files changed