Drop Profile from profile_sync_service_startup_unittest

Create ProfileSyncService directly from testing components, rather than
relying on Profile to inject them.

This CL also pulls some useful code from profile_sync_service_unittest into
the test utils, notably creating the ProfileSyncServiceBundle.

BUG=578823

Review URL: https://codereview.chromium.org/1624363003

Cr-Commit-Position: refs/heads/master@{#372311}
8 files changed