Add UMA for service worker navigation preload.

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 123 matching lines @@
   };
 
   // Not used for UMA.
   enum class StartSituation {
     UNKNOWN,
     DURING_STARTUP,
     EXISTING_PROCESS,
     NEW_PROCESS
   };
 
+  // Used for UMA. Append only.
+  // This enum describes how an activated worker was found and prepared (i.e.,
+  // reached the RUNNING status) in order to dispatch a fetch event to.
+  enum class WorkerPreparationType {
+    UNKNOWN,
+    // The worker was already starting up. We waited for it to finish.
+    STARTING,
+    // The worker was already running.
+    RUNNING,
+    // The worker was stopping. We waited for it to stop, and then started it
+    // up.
+    STOPPING,
+    // The worker was in the stopped state. We started it up, and startup
+    // required a new process to be created.
+    START_IN_NEW_PROCESS,
+    // The worker was in the stopped state. We started it up, and it used an
+    // existing process.
+    START_IN_EXISTING_PROCESS,
+    // The worker was in the stopped state. We started it up, and this occurred
+    // during browser startup.
+    START_DURING_STARTUP,
+    // Add new types here.
+    NUM_TYPES
+  };
+
   // Not used for UMA.
   enum class LoadSource { NETWORK, HTTP_CACHE, SERVICE_WORKER_STORAGE };
 
   // Converts an event type to a string. Used for tracing.
   static const char* EventTypeToString(EventType event_type);
 
   // If the |url| is not a special site, returns Site::OTHER.
   static Site SiteFromURL(const GURL& url);
 
   // Returns true when the event is for a navigation hint.
@@ skipping 32 matching lines @@
                                       EventType purpose,
                                       bool is_installed);
 
   // Records the time taken to successfully start a worker. |is_installed|
   // indicates whether the version has been installed.
   static void RecordStartWorkerTime(base::TimeDelta time,
                                     bool is_installed,
                                     StartSituation start_situation,
                                     EventType purpose);
 
-  // Records the time taken to prepare an activated Service Worker for a main
-  // frame fetch.
-  static void RecordActivatedWorkerPreparationTimeForMainFrame(
+  // Records metrics for the preparation of an activated Service Worker for a
+  // main frame navigation.
+  CONTENT_EXPORT static void RecordActivatedWorkerPreparationForMainFrame(
       base::TimeDelta time,
       EmbeddedWorkerStatus initial_worker_status,
-      StartSituation start_situation);
+      StartSituation start_situation,
+      bool did_navigation_preload);
 
   // Records the result of trying to stop a worker.
   static void RecordWorkerStopped(StopStatus status);
 
   // Records the time taken to successfully stop a worker.
   static void RecordStopWorkerTime(base::TimeDelta time);
 
   static void RecordActivateEventStatus(ServiceWorkerStatusCode status,
                                         bool is_shutdown);
   static void RecordInstallEventStatus(ServiceWorkerStatusCode status);
@@ skipping 86 matching lines @@
       bool is_installed,
       bool is_main_script);
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(ServiceWorkerMetrics);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_METRICS_H_