IDL: make optional arguments (without default) explicit sometimes

Source/modules/indexeddb/IDBObjectStore.idl

Index: Source/modules/indexeddb/IDBObjectStore.idl
diff --git a/Source/modules/indexeddb/IDBObjectStore.idl b/Source/modules/indexeddb/IDBObjectStore.idl
index a22fc74ad63970e7c21d9859decbc0a27cdeb33a..f91df62f8fc20862c72248d941bda2fdd5824730 100644
--- a/Source/modules/indexeddb/IDBObjectStore.idl
+++ b/Source/modules/indexeddb/IDBObjectStore.idl
@@ -42,17 +42,17 @@ enum IDBCursorDirection {
     readonly attribute IDBTransaction transaction;
     readonly attribute boolean autoIncrement;
 
-    [CallWith=ScriptState, RaisesException] IDBRequest put(any value, [Default=Undefined] optional any key);
-    [CallWith=ScriptState, RaisesException] IDBRequest add(any value, [Default=Undefined] optional any key);
+    [CallWith=ScriptState, RaisesException] IDBRequest put(any value, optional any key);
+    [CallWith=ScriptState, RaisesException] IDBRequest add(any value, optional any key);
     [CallWith=ScriptState, ImplementedAs=deleteFunction, RaisesException] IDBRequest delete(any key);
     [CallWith=ScriptState, RaisesException] IDBRequest get(any key);
     [CallWith=ScriptState, RaisesException] IDBRequest clear();
-    [CallWith=ScriptState, RaisesException] IDBRequest openCursor([Default=Undefined] optional any range, optional DOMString direction = "next");
-    [CallWith=ScriptState, RaisesException, RuntimeEnabled=IndexedDBExperimental] IDBRequest openKeyCursor([Default=Undefined] optional any range, optional IDBCursorDirection direction = "next");
+    [CallWith=ScriptState, RaisesException] IDBRequest openCursor(optional any range, optional DOMString direction = "next");
+    [CallWith=ScriptState, RaisesException, RuntimeEnabled=IndexedDBExperimental] IDBRequest openKeyCursor(optional any range, optional IDBCursorDirection direction = "next");
     // FIXME: should be union type http://crbug.com/240176
     [CallWith=ScriptState, RaisesException] IDBIndex createIndex(DOMString name, DOMString keyPath, optional Dictionary options);
     [CallWith=ScriptState, RaisesException] IDBIndex createIndex(DOMString name, sequence<DOMString> keyPath, optional Dictionary options);
     [RaisesException] IDBIndex index(DOMString name);
     [RaisesException] void deleteIndex(DOMString name);
-    [CallWith=ScriptState, RaisesException] IDBRequest count([Default=Undefined] optional any key);
+    [CallWith=ScriptState, RaisesException] IDBRequest count(optional any key);
 };