sdk/lib/html/dart2js/html_dart2js.dart

Index: sdk/lib/html/dart2js/html_dart2js.dart
diff --git a/sdk/lib/html/dart2js/html_dart2js.dart b/sdk/lib/html/dart2js/html_dart2js.dart
index ec9e4c41606952cc9122272346187a92d483c126..3ff4de478d50a34b5b81de3802c730fb7732a4fc 100644
--- a/sdk/lib/html/dart2js/html_dart2js.dart
+++ b/sdk/lib/html/dart2js/html_dart2js.dart
@@ -33352,19 +33352,6 @@ class Platform {
    * error.
    */
   static final supportsSimd = false;
-
-  /**
-   * Upgrade all custom elements in the subtree which have not been upgraded.
-   *
-   * This is needed to cover timing scenarios which the custom element polyfill
-   * does not cover.
-   */
-  static void upgradeCustomElements(Node node) {
-    if (JS('bool', '(#.CustomElements && #.CustomElements.upgradeAll)',
-        window, window)) {
-      JS('', '#.CustomElements.upgradeAll(#)', window, node);
-    }
-  }
 }
 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a