[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
SyncBackendHost::SyncBackendHost(Profile* profile)
    : weak_ptr_factory_(ALLOW_THIS_IN_INITIALIZER_LIST(this)),
      sync_thread_("Chrome_SyncThread"),
      frontend_loop_(MessageLoop::current()),
      profile_(profile),
      name_("Unknown"),
      initialization_state_(NOT_ATTEMPTED),
      chrome_sync_notification_bridge_(profile_),
      sync_notifier_factory_(
          ParseNotifierOptions(*CommandLine::ForCurrentProcess(),
                               profile_->GetRequestContext()),
          content::GetUserAgent(GURL()),
          base::WeakPtr<sync_notifier::InvalidationStateTracker>()),
      frontend_(NULL) {
}

SyncBackendHost::SyncBackendHost(Profile* profile)
    : weak_ptr_factory_(ALLOW_THIS_IN_INITIALIZER_LIST(this)),
      sync_thread_("Chrome_SyncThread"),
      frontend_loop_(MessageLoop::current()),
      profile_(profile),
      name_("Unknown"),
      initialization_state_(NOT_ATTEMPTED),
      chrome_sync_notification_bridge_(profile_),
      sync_notifier_factory_(
          ParseNotifierOptions(*CommandLine::ForCurrentProcess(),
                               profile_->GetRequestContext()),
          content::GetUserAgent(GURL()),
          base::WeakPtr<sync_notifier::InvalidationStateTracker>()),
      frontend_(NULL) {
}
