sync: remove Chrome OS specific logic to deal with flimflam shutdown / sync race.

No longer necessary as the ProfileSyncService now aborts sync network traffic on shutdown.

BUG=chromium-os:20841


Review URL: http://codereview.chromium.org/9358007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@120912 0039d316-1c4b-4281-b951-d872f2087c98
void SyncManager::RefreshNigori(const base::Closure& done_callback) {
  DCHECK(thread_checker_.CalledOnValidThread());
  data_->UpdateCryptographerAndNigori(base::Bind(
      &SyncManager::DoneRefreshNigori,
      base::Unretained(this),
      done_callback));
}

void SyncManager::RefreshNigori(const base::Closure& done_callback) {
  DCHECK(thread_checker_.CalledOnValidThread());
  data_->UpdateCryptographerAndNigori(base::Bind(
      &SyncManager::DoneRefreshNigori,
      base::Unretained(this),
      done_callback));
}
