Replace DOMWindow with iframe attrs: src, id, name

third_party/WebKit/Source/core/timing/PerformanceLongTaskTiming.idl

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // https://github.com/spanicker/longtasks
 [
     OriginTrialEnabled=LongTaskObserver,
 ] interface PerformanceLongTaskTiming : PerformanceEntry {
-    readonly attribute Window? culpritWindow;
+    readonly attribute DOMString culpritFrameSrc;
+    readonly attribute DOMString culpritFrameId;
+    readonly attribute DOMString culpritFrameName;
 };