title: IndexedDB methods with no arguments giving `TypeError` instead of `DataError`
body: <p>For certain methods (at least <code>IDBIndex.get</code>, <code>IDBIndex.getKey</code>, and <code>IDBObjectStore.delete</code>), passing in no arguments gives a <code>TypeError</code> whereas the corresponding steps in the spec do not mention this (and would instead suggest a <code>DataError</code>-type <code>DOMException</code>). Is this a bug in the spec or am I missing something?</p>