Add use counters for lots of DOM APIs.

third_party/WebKit/Source/core/events/MutationEvent.idl

 /*
  * Copyright (C) 2006 Apple Computer, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  */
 
 // https://w3c.github.io/uievents/#interface-MutationEvent
 
 interface MutationEvent : Event {
     // attrChangeType
     const unsigned short MODIFICATION = 1;
     const unsigned short ADDITION     = 2;
     const unsigned short REMOVAL      = 3;
 
-    readonly attribute Node?          relatedNode;
-    readonly attribute DOMString      prevValue;
-    readonly attribute DOMString      newValue;
-    readonly attribute DOMString      attrName;
-    readonly attribute unsigned short attrChange;
+    [Measure] readonly attribute Node?          relatedNode;
+    [Measure] readonly attribute DOMString      prevValue;
+    [Measure] readonly attribute DOMString      newValue;
+    [Measure] readonly attribute DOMString      attrName;
+    [Measure] readonly attribute unsigned short attrChange;
     // TODO(foolip): None of the initMutationEvent() arguments should be optional.
     [Measure] void initMutationEvent([Default=Undefined] optional DOMString type,
                                      [Default=Undefined] optional boolean bubbles,
                                      [Default=Undefined] optional boolean cancelable,
                                      [Default=Undefined] optional Node? relatedNode,
                                      [Default=Undefined] optional DOMString prevValue,
                                      [Default=Undefined] optional DOMString newValue,
                                      [Default=Undefined] optional DOMString attrName,
                                      [Default=Undefined] optional unsigned short attrChange);
 };