IDL: make optional arguments (without default) explicit sometimes

Source/modules/indexeddb/IDBObjectStore.h

Index: Source/modules/indexeddb/IDBObjectStore.h
diff --git a/Source/modules/indexeddb/IDBObjectStore.h b/Source/modules/indexeddb/IDBObjectStore.h
index ecd8d24a82d716d23216acb9e3ec6568ace566b4..fd8e05d05cdc74297e7423a8bee9672fd9a364da 100644
--- a/Source/modules/indexeddb/IDBObjectStore.h
+++ b/Source/modules/indexeddb/IDBObjectStore.h
@@ -69,8 +69,8 @@ public:
     IDBRequest* openCursor(ScriptState*, const ScriptValue& range, const String& direction, ExceptionState&);
     IDBRequest* openKeyCursor(ScriptState*, const ScriptValue& range, const String& direction, ExceptionState&);
     IDBRequest* get(ScriptState*, const ScriptValue& key, ExceptionState&);
-    IDBRequest* add(ScriptState*, ScriptValue&, const ScriptValue& key, ExceptionState&);
-    IDBRequest* put(ScriptState*, ScriptValue&, const ScriptValue& key, ExceptionState&);
+    IDBRequest* add(ScriptState*, const ScriptValue&, const ScriptValue& key, ExceptionState&);
+    IDBRequest* put(ScriptState*, const ScriptValue&, const ScriptValue& key, ExceptionState&);
     IDBRequest* deleteFunction(ScriptState*, const ScriptValue& key, ExceptionState&);
     IDBRequest* clear(ScriptState*, ExceptionState&);
 
@@ -88,7 +88,7 @@ public:
     IDBRequest* count(ScriptState*, const ScriptValue& range, ExceptionState&);
 
     // Used by IDBCursor::update():
-    IDBRequest* put(ScriptState*, WebIDBPutMode, IDBAny* source, ScriptValue&, IDBKey*, ExceptionState&);
+    IDBRequest* put(ScriptState*, WebIDBPutMode, IDBAny* source, const ScriptValue&, IDBKey*, ExceptionState&);
 
     // Used internally and by InspectorIndexedDBAgent:
     IDBRequest* openCursor(ScriptState*, IDBKeyRange*, WebIDBCursorDirection, WebIDBTaskType = WebIDBTaskTypeNormal);
@@ -109,7 +109,7 @@ private:
 
     IDBIndex* createIndex(ScriptState*, const String& name, const IDBKeyPath&, const Dictionary&, ExceptionState&);
     IDBIndex* createIndex(ScriptState*, const String& name, const IDBKeyPath&, bool unique, bool multiEntry, ExceptionState&);
-    IDBRequest* put(ScriptState*, WebIDBPutMode, IDBAny* source, ScriptValue&, const ScriptValue& key, ExceptionState&);
+    IDBRequest* put(ScriptState*, WebIDBPutMode, IDBAny* source, const ScriptValue&, const ScriptValue& key, ExceptionState&);
 
     int64_t findIndexId(const String& name) const;
     bool containsIndex(const String& name) const