[Sync] Cleanup all tab sync enabling logic now that its on by default.

BUG=none
TEST=


Review URL: https://chromiumcodereview.appspot.com/10443046

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@139462 0039d316-1c4b-4281-b951-d872f2087c98
void SyncBackendHost::Core::OnUpdatedToken(const std::string& token) {
  if (!sync_loop_)
    return;
  DCHECK_EQ(MessageLoop::current(), sync_loop_);
  host_.Call(
      FROM_HERE,
      &SyncBackendHost::NotifyUpdatedToken, token);
}

void SyncBackendHost::Core::OnUpdatedToken(const std::string& token) {
  if (!sync_loop_)
    return;
  DCHECK_EQ(MessageLoop::current(), sync_loop_);
  host_.Call(
      FROM_HERE,
      &SyncBackendHost::NotifyUpdatedToken, token);
}
