Instrument direct surfaces of Gamepad.

Bug: 973801
Change-Id: Ie07f6fc6e2f86bcfc1c81ec49335cc3bcbf19c5c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2363850
Commit-Queue: Caleb Raitto <caraitto@chromium.org>
Reviewed-by: Brandon Jones <bajones@chromium.org>
Cr-Commit-Position: refs/heads/master@{#800168}

third_party/blink/public/mojom/web_feature/web_feature.mojom

@@ -2760,6 +2760,7 @@ enum WebFeature {
   kBluetoothAdvertisingEventAppearance = 3431,
   kBluetoothAdvertisingEventTxPower = 3432,
   kCrossOriginOpenerPolicyReporting= 3433,
+  kGamepadId = 3434,
 
   // Add new features immediately above this line. Don't change assigned
   // numbers of any item, and don't reuse removed slots.

third_party/blink/renderer/modules/gamepad/gamepad.idl

@@ -36,7 +36,7 @@ enum GamepadMappingType {
 [
     Exposed=Window
 ] interface Gamepad {
-    readonly attribute DOMString id;
+    [HighEntropy=Direct, MeasureAs=GamepadId] readonly attribute DOMString id;
     readonly attribute long index;
     readonly attribute boolean connected;
     readonly attribute DOMHighResTimeStamp timestamp;

tools/metrics/histograms/enums.xml

@@ -28865,6 +28865,7 @@ Called by update_use_counter_feature_enum.py.-->
   <int value="3431" label="BluetoothAdvertisingEventAppearance"/>
   <int value="3432" label="BluetoothAdvertisingEventTxPower"/>
   <int value="3433" label="CrossOriginOpenerPolicyReporting"/>
+  <int value="3434" label="GamepadId"/>
 </enum>
 
 <enum name="FeaturePolicyAllowlistType">