Add status() DCHECK to ServiceWorkerVersion::StartRequest.

content/browser/service_worker/service_worker_metrics.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_METRICS_H_
 #define CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_METRICS_H_
 
 #include <stddef.h>
 
 #include "base/macros.h"
@@ skipping 64 matching lines @@
   // Used for UMA. Append-only.
   enum class EventType {
     ACTIVATE,
     INSTALL,
     FETCH,
     SYNC,
     NOTIFICATION_CLICK,
     PUSH,
     GEOFENCING,
     SERVICE_PORT_CONNECT,
+    MESSAGE,

[nhiroki, 2016/01/20 04:46:01]

Can you update a corresponding UMA enum in histograms.xml?

I know this is not used for recording for now, but it would be better to keep
consistency because we may forget to update when it's actually used. 

     // Add new events to record here.
 
     NUM_TYPES
   };
 
   // Used for UMA. Append only.
   enum class Site { OTHER, NEW_TAB_PAGE, NUM_TYPES };
 
   // Excludes NTP scope from UMA for now as it tends to dominate the stats and
   // makes the results largely skewed. Some metrics don't follow this policy
@@ skipping 78 matching lines @@
   // previous event ended).
   static void RecordTimeBetweenEvents(const base::TimeDelta& time);
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(ServiceWorkerMetrics);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_METRICS_H_