Add use counters for lots of DOM APIs.

third_party/WebKit/Source/modules/gamepad/Gamepad.idl

 /*
  * Copyright (C) 2011, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 13 matching lines @@
  */
 
 // https://w3c.github.io/gamepad/extensions.html#gamepadhand-enum
 enum GamepadHand {
   "left",
   "right"
 };
 
 // https://w3c.github.io/gamepad/#gamepad-interface
 interface Gamepad {
-    readonly attribute DOMString id;
-    readonly attribute unsigned long index;
-    readonly attribute boolean connected;
-    readonly attribute unsigned long long timestamp;
-    readonly attribute DOMString mapping;
+    [Measure] readonly attribute DOMString id;
+    [Measure] readonly attribute unsigned long index;
+    [Measure] readonly attribute boolean connected;
+    [Measure] readonly attribute unsigned long long timestamp;
+    [Measure] readonly attribute DOMString mapping;
     // https://github.com/w3c/gamepad/issues/28
-    readonly attribute double[] axes;
-    readonly attribute GamepadButton[] buttons;
+    [Measure] readonly attribute double[] axes;
+    [Measure] readonly attribute GamepadButton[] buttons;
 
     [OriginTrialEnabled=GamepadExtensions, MeasureAs=GamepadPose] readonly attribute GamepadPose? pose;
     [OriginTrialEnabled=GamepadExtensions, MeasureAs=GamepadHand] readonly attribute GamepadHand hand;
 
     // https://w3c.github.io/webvr/#interface-gamepad
     [OriginTrialEnabled=GamepadExtensions, MeasureAs=GamepadDisplayId] readonly attribute unsigned long displayId;
 };