sync: Follow-up to conflict resolution refactor

This is part two of r164286.  That commit refactored the way we handle
conflict resolution.  This commit takes advantage of those changes to
delete lots of code.

Because this change deletes session_state.cc, I decided to move the two
remaining useful tests session_state_unittest.cc into their own files,
sync_session_snapshot_unittest.cc and sync_source_info_unittest.cc.  The
tests were not modified in any way.

None of these changes should have any effect on syncer behaviour:
- We can remove the simple conflict counters and related code, since we
  now assert that all conflicts will be resolved by the end of a
  successful sync cycle.
- We can remove the PerModelSafeGroupState because that struct no longer
  has any members.
- The 'conflicts_resolved' indicators are no longer set, so we can
  remove them.
- Without those indicators, it's no longer possible to have any
  SYNC_CYCLE_CONTINUATION sync cycles.  We can remove a few counters
  associated with them, as well as the 'has_more_to_sync' flag in the
  snapshot.
- Without SYNC_CYCLE_CONTINUATION cycles, there's no longer any need for
  code that loops around SyncShare() in SyncSchedulerImpl.  The
  SyncSession::PrepareForAnotherSyncCycle() function is no longer used,
  either.
- The ScopedConflictResolver installed on the session during a sync
  cycle is no longer used, so all the code related to it can be deleted.

BUG=147681,111280,156238


Review URL: https://chromiumcodereview.appspot.com/11314008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@165474 0039d316-1c4b-4281-b951-d872f2087c98

0 files changed, 0 insertions, 0 deletions