ServiceWorker: Enable UseCounter for ServiceWorkerGlobalScope

content/browser/service_worker/service_worker_database.proto

Index: content/browser/service_worker/service_worker_database.proto
diff --git a/content/browser/service_worker/service_worker_database.proto b/content/browser/service_worker/service_worker_database.proto
index 3ae7551f30a2337597569d228641383008844b84..d0a1f2f1d0184f24b35c291b96499af81db031fa 100644
--- a/content/browser/service_worker/service_worker_database.proto
+++ b/content/browser/service_worker/service_worker_database.proto
@@ -50,6 +50,10 @@ message ServiceWorkerRegistrationData {
   optional ServiceWorkerOriginTrialInfo origin_trial_tokens = 11;
 
   optional ServiceWorkerNavigationPreloadState navigation_preload_state = 12;
+
+  // The set of features that the worker has used. The values must be from
+  // blink::UseCounter::Feature enum.

[falken, 2017/02/08 05:01:53]

This is the set of features the worker used up until the time installation
completed right? Could the comment reflect that?

[nhiroki, 2017/02/09 05:11:31]

That's right. Updated.

+  repeated uint32 used_features = 13;
 }
 
 message ServiceWorkerResourceRecord {