Implement IDBVersionChangeEvent ctor w/ IDBVersionChangeEventInit dict

Source/modules/indexeddb/IDBVersionChangeEvent.idl

Index: Source/modules/indexeddb/IDBVersionChangeEvent.idl
diff --git a/Source/modules/indexeddb/IDBVersionChangeEvent.idl b/Source/modules/indexeddb/IDBVersionChangeEvent.idl
index 2d81f437ed581d1c3e135dd4ef95e0e4a45e0bd8..e504616b2557aa23c8abb824f0de3f4f184e306d 100644
--- a/Source/modules/indexeddb/IDBVersionChangeEvent.idl
+++ b/Source/modules/indexeddb/IDBVersionChangeEvent.idl
@@ -23,9 +23,11 @@
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-interface IDBVersionChangeEvent : Event {
-    [CallWith=ExecutionContext] readonly attribute any oldVersion;
-    [CallWith=ExecutionContext] readonly attribute any newVersion;
+[
+    EventConstructor
+] interface IDBVersionChangeEvent : Event {
+    [InitializedByEventConstructor] readonly attribute SerializedScriptValue oldVersion;
+    [InitializedByEventConstructor] readonly attribute SerializedScriptValue newVersion;
 
     // FIXME: These are non-standard, see
     // https://www.w3.org/Bugs/Public/show_bug.cgi?id=22370