Add use counters for lots of DOM APIs.

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

Index: third_party/WebKit/Source/modules/gamepad/Gamepad.idl
diff --git a/third_party/WebKit/Source/modules/gamepad/Gamepad.idl b/third_party/WebKit/Source/modules/gamepad/Gamepad.idl
index 8756cb400e1b68e98bc65e5413665f934c4164b1..b95dced201c8fce0853187e480407c52f317a019 100644
--- a/third_party/WebKit/Source/modules/gamepad/Gamepad.idl
+++ b/third_party/WebKit/Source/modules/gamepad/Gamepad.idl
@@ -31,14 +31,14 @@ enum GamepadHand {
 
 // 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;