Add use counters to determine the fate of DOMStringList

Source/modules/indexeddb/IDBDatabase.idl

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 16 matching lines @@
 // https://w3c.github.io/IndexedDB/#idl-def-IDBDatabase
 
 [
     Exposed=(Window,Worker),
     ActiveDOMObject,
     GarbageCollected,
 ] interface IDBDatabase : EventTarget {
     readonly attribute DOMString name;
     // TODO(jsbell): DOMString version is non-standard, to support databases created with old API.
     readonly attribute (unsigned long long or DOMString) version;
-    readonly attribute DOMStringList objectStoreNames;
+    [Measure] readonly attribute DOMStringList objectStoreNames;
 
     [RaisesException] IDBObjectStore createObjectStore(DOMString name, optional IDBObjectStoreParameters options);
     [RaisesException] void deleteObjectStore(DOMString name);
     [CallWith=ScriptState, RaisesException] IDBTransaction transaction((DOMString or sequence<DOMString> or DOMStringList) storeNames, optional IDBTransactionMode mode = "readonly");
     void close();
 
     attribute EventHandler onabort;
     attribute EventHandler onclose;
     attribute EventHandler onerror;
     attribute EventHandler onversionchange;
 };