Have bindings layer assume and insist that all interface types are GCed.

third_party/WebKit/Source/modules/indexeddb/IDBTransaction.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 20 matching lines @@
     "readwrite",
     "versionchange"
 };
 
 // https://w3c.github.io/IndexedDB/#idl-def-IDBTransaction
 
 [
     ActiveScriptWrappable,
     DependentLifetime,
     Exposed=(Window,Worker),
-    GarbageCollected,
 ] interface IDBTransaction : EventTarget {
 
     // Properties
     [Measure] readonly attribute DOMStringList objectStoreNames;
     readonly attribute IDBTransactionMode mode;
     readonly attribute IDBDatabase db;
     readonly attribute DOMException error;
 
     // Methods
     [RaisesException] IDBObjectStore objectStore (DOMString name);
     [RaisesException] void abort ();
 
     // Events
     attribute EventHandler onabort;
     attribute EventHandler oncomplete;
     attribute EventHandler onerror;
 };