Roll 50: Copied IDLs, PYTHON scripts from WebKit removed deleted files in WebCore

core/frame/NavigatorStorageUtils.idl

 // Copyright 2015 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://html.spec.whatwg.org/#manually-releasing-the-storage-mutex
 
 [
     NoInterfaceObject, // Always used on target of 'implements'
 ] interface NavigatorStorageUtils {
     readonly attribute boolean cookieEnabled;
-    // TODO(philipj): This is called yieldForStorageUpdates() in the spec.
-    [Measure] void getStorageUpdates();
 };