service worker: Add UMA for start status grouped by start purpose.

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 62 matching lines @@
     DETACH_BY_REGISTRY,
     TIMEOUT,
     // Add new types here.
     NUM_TYPES
   };
 
   // Used for UMA. Append-only.
   enum class EventType {
     ACTIVATE = 0,
     INSTALL = 1,
-    DEPRECATED_FETCH = 2,  // Deprecated, use a more specific FETCH_ type.
+    // DEPRECATED_FETCH = 2,
     SYNC = 3,
     NOTIFICATION_CLICK = 4,
     PUSH = 5,
     GEOFENCING = 6,
     // SERVICE_PORT_CONNECT = 7,

[nhiroki, 2016/04/26 06:05:20]

DEPRECATED_SERVICE_PORT_CONNECT?

[falken, 2016/04/26 06:11:20]

Right, I guess it should be consistent with above. I changed these to have an //
Obsolete comment.

     MESSAGE = 8,
     NOTIFICATION_CLOSE = 9,
     FETCH_MAIN_FRAME = 10,
     FETCH_SUB_FRAME = 11,
     FETCH_SHARED_WORKER = 12,
     FETCH_SUB_RESOURCE = 13,
     UNKNOWN = 14,  // Used when event type is not known.
     FOREIGN_FETCH = 15,
     // Add new events to record here.
     NUM_TYPES
@@ skipping 121 matching lines @@
   static void RecordStartStatusAfterFailure(int failure_count,
                                             ServiceWorkerStatusCode status);
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(ServiceWorkerMetrics);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_METRICS_H_