Introduce ServiceWorker.ActivatedWorkerPreparationForMainFrame.Time UMA.

content/browser/service_worker/embedded_worker_instance.h

 // 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.
 
 #ifndef CONTENT_BROWSER_SERVICE_WORKER_EMBEDDED_WORKER_INSTANCE_H_
 #define CONTENT_BROWSER_SERVICE_WORKER_EMBEDDED_WORKER_INSTANCE_H_
 
 #include <stdint.h>
 
 #include <memory>
 #include <string>
 
 #include "base/callback.h"
 #include "base/callback_forward.h"
 #include "base/gtest_prod_util.h"
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
 #include "base/observer_list.h"
 #include "base/strings/string16.h"
 #include "base/time/time.h"
+#include "content/browser/service_worker/embedded_worker_status.h"
 #include "content/browser/service_worker/service_worker_metrics.h"
 #include "content/common/content_export.h"
 #include "content/common/service_worker/service_worker_status_code.h"
 #include "content/public/common/console_message_level.h"
 #include "url/gurl.h"
 
 // Windows headers will redefine SendMessage.
 #ifdef SendMessage
 #undef SendMessage
 #endif
@@ skipping 11 matching lines @@
 class ServiceRegistry;
 class ServiceRegistryImpl;
 class ServiceWorkerContextCore;
 
 // This gives an interface to control one EmbeddedWorker instance, which
 // may be 'in-waiting' or running in one of the child processes added by
 // AddProcessReference().
 class CONTENT_EXPORT EmbeddedWorkerInstance {
  public:
   typedef base::Callback<void(ServiceWorkerStatusCode)> StatusCallback;
-  enum Status {
-    STOPPED,
-    STARTING,
-    RUNNING,
-    STOPPING,
-  };
+  typedef EmbeddedWorkerStatus Status;

[falken, 2016/06/07 03:46:12]

I think it's now:
using EmbeddedWorkerStatus = Status

But I tend to prefer to just write out EmbeddedWorkerStatus to eliminate the
level of indirection.

[horo, 2016/06/07 05:58:12]

Done.

 
   // This enum is used in UMA histograms. Append-only.
   enum StartingPhase {
     NOT_STARTING,
     ALLOCATING_PROCESS,
     REGISTERING_TO_DEVTOOLS,
     SENT_START_WORKER,
     SCRIPT_DOWNLOADING,
     SCRIPT_LOADED,
     SCRIPT_EVALUATED,
@@ skipping 65 matching lines @@
   // Resumes the worker if it paused after download.
   void ResumeAfterDownload();
 
   // Returns the ServiceRegistry for this worker. It is invalid to call this
   // when the worker is not in STARTING or RUNNING status.
   ServiceRegistry* GetServiceRegistry();
 
   int embedded_worker_id() const { return embedded_worker_id_; }
   Status status() const { return status_; }
   StartingPhase starting_phase() const {
-    DCHECK_EQ(STARTING, status());
+    DCHECK_EQ(Status::STARTING, status());
     return starting_phase_;
   }
   int process_id() const;
   int thread_id() const { return thread_id_; }
   // This should be called only when the worker instance has a valid process,
   // that is, when |process_id()| returns a valid process id.
   bool is_new_process() const;
   int worker_devtools_agent_route_id() const;
   MessagePortMessageFilter* message_port_message_filter() const;
 
   void AddListener(Listener* listener);
   void RemoveListener(Listener* listener);
 
   void set_devtools_attached(bool attached) { devtools_attached_ = attached; }
   bool devtools_attached() const { return devtools_attached_; }
 
   bool network_accessed_for_script() const {
     return network_accessed_for_script_;
   }
 
+  ServiceWorkerMetrics::StartSituation start_situation() const {

[falken, 2016/06/07 03:46:12]

Does it make sense to have DCHECK(STARTING || RUNNING) here?

[horo, 2016/06/07 05:58:12]

Done.

+    return start_situation_;
+  }
+
   // Called when the main script load accessed the network.
   void OnNetworkAccessedForScriptLoad();
 
   // Called when reading the main script from the service worker script cache
   // begins and ends.
   void OnScriptReadStarted();
   void OnScriptReadFinished();
 
   // Called when the worker is installed.
   void OnWorkerVersionInstalled();
@@ skipping 25 matching lines @@
   FRIEND_TEST_ALL_PREFIXES(EmbeddedWorkerInstanceTest, StartAndStop);
   FRIEND_TEST_ALL_PREFIXES(EmbeddedWorkerInstanceTest, DetachDuringStart);
   FRIEND_TEST_ALL_PREFIXES(EmbeddedWorkerInstanceTest, StopDuringStart);
 
   // Constructor is called via EmbeddedWorkerRegistry::CreateWorker().
   // This instance holds a ref of |registry|.
   EmbeddedWorkerInstance(base::WeakPtr<ServiceWorkerContextCore> context,
                          int embedded_worker_id);
 
   // Called back from StartTask after a process is allocated on the UI thread.
-  void OnProcessAllocated(std::unique_ptr<WorkerProcessHandle> handle);
+  void OnProcessAllocated(std::unique_ptr<WorkerProcessHandle> handle,
+                          ServiceWorkerMetrics::StartSituation start_situation);
 
   // Called back from StartTask after the worker is registered to
   // WorkerDevToolsManager.
   void OnRegisteredToDevToolsManager(bool is_new_process,
                                      int worker_devtools_agent_route_id,
                                      bool wait_for_debugger);
 
   // Called back from StartTask after a start worker message is sent.
   void OnStartWorkerMessageSent();
 
@@ skipping 80 matching lines @@
 
   // True if the script load request accessed the network. If the script was
   // served from HTTPCache or ServiceWorkerDatabase this value is false.
   bool network_accessed_for_script_;
 
   ListenerList listener_list_;
   std::unique_ptr<DevToolsProxy> devtools_proxy_;
 
   std::unique_ptr<StartTask> inflight_start_task_;
 
+  ServiceWorkerMetrics::StartSituation start_situation_ =
+      ServiceWorkerMetrics::StartSituation::UNKNOWN;

[falken, 2016/06/07 03:46:12]

It's a little unfortunate this state has to move out of StartTask. Can you add
comments about when this member is valid?

[horo, 2016/06/07 05:58:12]

Done.

+
   // Used for UMA. The start time of the current start sequence step.
   base::TimeTicks step_time_;
 
   base::WeakPtrFactory<EmbeddedWorkerInstance> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(EmbeddedWorkerInstance);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_SERVICE_WORKER_EMBEDDED_WORKER_INSTANCE_H_