Update ServiceWorker event handled status histogram

content/browser/service_worker/service_worker_metrics.h

Index: content/browser/service_worker/service_worker_metrics.h
diff --git a/content/browser/service_worker/service_worker_metrics.h b/content/browser/service_worker/service_worker_metrics.h
index dcac6dc2d6ac0e710395f6fe13fa4cd72f15b776..31fed9114303ed401d13af24f91d1219d24bd684 100644
--- a/content/browser/service_worker/service_worker_metrics.h
+++ b/content/browser/service_worker/service_worker_metrics.h
@@ -65,6 +65,12 @@ class ServiceWorkerMetrics {
     NUM_REQUEST_JOB_RESULT_TYPES,
   };
 
+  enum EventType {
+    EVENT_TYPE_FETCH,
+    // Add new event to record here.
+    EVENT_TYPE_MAX,

[falken, 2015/06/25 09:31:39]

the histogram people encouraged us to use NUM_EVENT_TYPES instead of MAX

[kinuko, 2015/07/02 14:27:26]

Done.

+  };
+
   // Used for ServiceWorkerDiskCache.
   static void CountInitDiskCacheResult(bool result);
   static void CountReadResponseResult(ReadResponseResult result);
@@ -98,7 +104,15 @@ class ServiceWorkerMetrics {
 
   // Records the ratio of unhandled events to the all events fired during
   // the lifetime of ServiceWorker.
-  static void RecordEventStatus(size_t fired_events, size_t handled_events);
+  static void RecordPerWorkerEventHandledStatus(const GURL& scope,
+                                                EventType event,
+                                                size_t handled_events,
+                                                size_t fired_events);
+
+  // Records if each ServiceWorker event is handled or not.
+  static void RecordEventHandledStatus(const GURL& scope,
+                                       EventType event,
+                                       bool handled);
 
   // Records result of a ServiceWorkerURLRequestJob that was forwarded to
   // the service worker.