Quota double-delete fix

BUG=142310


Review URL: https://chromiumcodereview.appspot.com/10832407

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@152532 0039d316-1c4b-4281-b951-d872f2087c98
QuotaTask::~QuotaTask() {
}

QuotaTask::~QuotaTask() {
}
