service worker: Add net_log for fetch event dispatch

net/log/net_log_event_type_list.h

Index: net/log/net_log_event_type_list.h
diff --git a/net/log/net_log_event_type_list.h b/net/log/net_log_event_type_list.h
index 24d0ad4a113983a14d99e607b4d9a73bb9571042..b85a9a3603d96248d229abfbb12609ef9757f91b 100644
--- a/net/log/net_log_event_type_list.h
+++ b/net/log/net_log_event_type_list.h
@@ -2097,6 +2097,44 @@ EVENT_TYPE(SERVICE_WORKER_WAITING_FOR_REQUEST_BODY_BLOB)
 // constructed.
 EVENT_TYPE(SERVICE_WORKER_ERROR_REQUEST_BODY_BLOB_FAILED)
 
+// The start/end of dispatching a fetch event to a service worker. This includes
+// waiting for the worker to activate and starting the worker if neccessary.
+//
+// The BEGIN phase consists of the following parameters:
+// {
+//   "event_type": A string indicating the type of fetch event. Generally it is
+//   either a fetch or foreignfetch event; fetch events are additionally
+//   categorized by resource type.
+// }
+//
+// For the END phase, the following parameters are attached. No parameters are
+// attached when cancelled:
+// {
+//   "status": The ServiceWorkerStatusCode as a string.
+//   "has_response": True if the service worker provided a response to the fetch
+//   event. False means to fall back to network.
+// }
+EVENT_TYPE(SERVICE_WORKER_DISPATCH_FETCH_EVENT)
+
+// Measures the time waiting for a service worker to go from ACTIVATING to
+// ACTIVATED.
+EVENT_TYPE(SERVICE_WORKER_WAIT_FOR_ACTIVATION)
+
+// The start/end of starting a service worker.
+// For the END phase, the following parameters are attached:
+// {
+//   "status": The ServiceWorkerStatusCode as a string. Only present on failure.
+// }
+EVENT_TYPE(SERVICE_WORKER_START_WORKER)
+
+// The start/end of dispatching a fetch event to an activated, running service
+// worker.
+// For the END phase, the following parameters are attached:
+// {
+//   "status": The ServiceWorkerStatusCode as a string. Only present on failure.
+// }
+EVENT_TYPE(SERVICE_WORKER_FETCH_EVENT)
+
 // ------------------------------------------------------------------------
 // Global events
 // ------------------------------------------------------------------------