Add use counters for lots of DOM APIs.

third_party/WebKit/Source/core/dom/DocumentOrShadowRoot.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://dom.spec.whatwg.org/#mixin-documentorshadowroot
 // https://w3c.github.io/webcomponents/spec/shadow/#extensions-to-the-documentorshadowroot-mixin
 [
     LegacyTreatAsPartialInterface,
     NoInterfaceObject,
 ] interface DocumentOrShadowRoot {
     // Selection API
     // https://w3c.github.io/selection-api/#extensions-to-document-interface
-    Selection? getSelection();
+    [Measure] Selection? getSelection();
     // CSSOM View Module
     // https://dev.w3.org/csswg/cssom-view/#extensions-to-the-document-interface
     // TODO(foolip): The x and y arguments should be of type double.
     Element? elementFromPoint(long x, long y);
     sequence<Element> elementsFromPoint(long x, long y);
     readonly attribute Element? activeElement;
     [SameObject] readonly attribute StyleSheetList styleSheets;
     // PointerLock API
     // https://w3c.github.io/pointerlock/
-    readonly attribute Element? pointerLockElement;
+    [Measure] readonly attribute Element? pointerLockElement;
     // Fullscreen API
     // https://fullscreen.spec.whatwg.org/
     [RuntimeEnabled=FullscreenUnprefixed] readonly attribute Element? fullscreenElement;
 };