Wipe out QuotaThreadTask.

This is a one of a series of refactoring patches for QuotaManager.
http://codereview.chromium.org/10872054/
http://codereview.chromium.org/10917060/

BUG=139270

Review URL: https://chromiumcodereview.appspot.com/10919070

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@154987 0039d316-1c4b-4281-b951-d872f2087c98
void QuotaManager::DeleteOriginData(
    const GURL& origin, StorageType type, int quota_client_mask,
    const StatusCallback& callback) {
  LazyInitialize();

  if (origin.is_empty() || clients_.empty()) {
    callback.Run(kQuotaStatusOk);
    return;
  }

  OriginDataDeleter* deleter =
      new OriginDataDeleter(this, origin, type, quota_client_mask, callback);
  deleter->Start();
}

void QuotaManager::DeleteOriginData(
    const GURL& origin, StorageType type, int quota_client_mask,
    const StatusCallback& callback) {
  LazyInitialize();

  if (origin.is_empty() || clients_.empty()) {
    callback.Run(kQuotaStatusOk);
    return;
  }

  OriginDataDeleter* deleter =
      new OriginDataDeleter(this, origin, type, quota_client_mask, callback);
  deleter->Start();
}
