service worker: Attribute purpose to start worker attempts for UMA

content/browser/service_worker/service_worker_dispatcher_host_unittest.cc

 // Copyright 2013 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.
 
 #include "content/browser/service_worker/service_worker_dispatcher_host.h"
 
 #include <stdint.h>
 #include <utility>
 
 #include "base/command_line.h"
@@ skipping 547 matching lines @@
       version.get(),
       base::Bind(&SaveStatusCallback, &called, &status));
   base::RunLoop().RunUntilIdle();
   EXPECT_TRUE(called);
   ASSERT_EQ(SERVICE_WORKER_OK, status);
 
   helper_->SimulateAddProcessToPattern(pattern, process_id);
 
   // Start up the worker.
   status = SERVICE_WORKER_ERROR_ABORT;
-  version->StartWorker(base::Bind(&SaveStatusCallback, &called, &status));
+  version->StartWorker(ServiceWorkerMetrics::EventType::UNKNOWN,
+                       base::Bind(&SaveStatusCallback, &called, &status));
   base::RunLoop().RunUntilIdle();
 
   EXPECT_TRUE(called);
   EXPECT_EQ(SERVICE_WORKER_OK, status);
 
   EXPECT_TRUE(context()->GetProviderHost(process_id, kProviderId));
   EXPECT_EQ(ServiceWorkerVersion::RUNNING, version->running_status());
 
   // Simulate the render process crashing.
   dispatcher_host_->OnFilterRemoved();
@@ skipping 11 matching lines @@
 
   // To show the new dispatcher can operate, simulate provider creation. Since
   // the old dispatcher cleaned up the old provider host, the new one won't
   // complain.
   new_dispatcher_host->OnMessageReceived(ServiceWorkerHostMsg_ProviderCreated(
       kProviderId, MSG_ROUTING_NONE, SERVICE_WORKER_PROVIDER_FOR_WINDOW));
   EXPECT_EQ(0, new_dispatcher_host->bad_messages_received_count_);
 }
 
 }  // namespace content