Activate the VariationsService for ChromeOS and ensure that it does not ping the server until the E…

chrome/browser/metrics/variations/resource_request_allowed_notifier.h

+// Copyright (c) 2012 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 CHROME_BROWSER_METRICS_VARIATIONS_RESOURCE_REQUEST_ALLOWED_NOTIFIER_H_
+#define CHROME_BROWSER_METRICS_VARIATIONS_RESOURCE_REQUEST_ALLOWED_NOTIFIER_H_
+
+#include "base/observer_list.h"
+#include "net/base/network_change_notifier.h"
+
+#if defined(OS_CHROMEOS)
+#include "content/public/browser/notification_observer.h"
+#include "content/public/browser/notification_registrar.h"
+#endif
+
+// This class informs an interested observer when resource requests over the
+// network are permitted.
+//
+// Currently, the criteria for allowing resource requests include:
+//  1. The network is currently available.
+//  2. The EULA was accepted by the user (ChromeOS only).
+//
+// Interested services should add themselves as an observer of
+// ResourceRequestAllowedNotifier and check ResourceRequestsAllowed() to see if
+// requests are permitted. If it returns true, they can go ahead and make their
+// request. If it returns false, ResourceRequestAllowedNotifier will notify the
+// service when the criteria is met.
+//
+// If ResourceRequestsAllowed returns true the first time,
+// ResourceRequestAllowedNotifier will not notify the service in the future.
+//
+// Note that this class handles the criteria state for a single service, so
+// services should keep their own instance of this class rather than sharing a
+// global instance.
+class ResourceRequestAllowedNotifier :
+#if defined(OS_CHROMEOS)
+    public content::NotificationObserver,
+#endif
+    public net::NetworkChangeNotifier::ConnectionTypeObserver {
+ public:
+  // Observes resource request allowed state changes.
+  class Observer {
+   public:
+    virtual void OnResourceRequestsAllowed() = 0;
+  };
+
+  ResourceRequestAllowedNotifier();
+  virtual ~ResourceRequestAllowedNotifier();
+
+  // Sets |observer| as the service to be notified by this instance, and
+  // performs initial checks on the criteria. |observer| may not be NULL.
+  // This is to be called immediately after construction of an instance of
+  // ResourceRequestAllowedNotifier to pass it the interested service.
+  void Init(Observer* observer);
+
+  // Returns true iff all resource request criteria are met. If not, this call
+  // will set some flags so it knows to notify the observer if the criteria
+  // changes. Note that the observer will never be notified unless it calls this
+  // method first. This is virtual so it can be overriden for tests.
+  virtual bool ResourceRequestsAllowed();
+
+  void SetObserverRequestedPermissionForTesting(bool requested);

[Alexei Svitkine (slow), 2012/09/24 20:47:05]

Instead of this method, can the test simply call ResourceRequestAllowed()?

[SteveT, 2012/09/24 23:30:37]

Some refactoring done to make this happen.

Please see TestRequestAllowedNotifier::ResourceRequestsAllowed's definition and
let me know if that's acceptable... It's the only way to do your way without
keeping this ForTesting method (aside from making a field private->protected).

+  void SetWasWaitingForNetworkForTesting(bool waiting);
+#if defined(OS_CHROMEOS)
+  void SetWasWaitingForEulaForTesting(bool waiting);
+#endif
+
+ protected:
+  // Notifies observers if all criteria needed for resource requests are met.

[Alexei Svitkine (slow), 2012/09/24 20:47:05]

Nit: "observers" -> "observer".

[SteveT, 2012/09/24 23:30:37]

Done.

+  // This is protected so it can be called from subclasses for testing.
+  void MaybeNotifyObserver();
+
+#if defined(OS_CHROMEOS)
+  // On official builds, returns true iff the EULA needs to be accepted. This
+  // always returns false on unofficial builds since there is no notion of a
+  // EULA.
+  //
+  // This is virtual so it can be overriden by test classes to avoid making them
+  // aware of the ChromeOS details. This is protected so it call be overriden in
+  // subclasses for testing.
+  virtual bool NeedsEulaAcceptance();
+#endif
+
+ private:
+  // net::NetworkChangeNotifier::ConnectionTypeObserver overrides:
+  virtual void OnConnectionTypeChanged(
+      net::NetworkChangeNotifier::ConnectionType type) OVERRIDE;
+
+#if defined(OS_CHROMEOS)
+  // content::NotificationObserver overrides:
+  virtual void Observe(int type,
+                       const content::NotificationSource& source,
+                       const content::NotificationDetails& details) OVERRIDE;
+#endif
+
+  // Tracks whether or not the observer/service depending on this class actually
+  // requested permission to make a request or not. If it did not, then this
+  // class should not notify it even if the criteria is met.
+  bool observer_requested_permission_;
+
+  // Tracks network connectivity criteria.
+  bool was_waiting_for_network_;
+
+#if defined(OS_CHROMEOS)
+  // Tracks EULA acceptance criteria.
+  bool was_waiting_for_user_to_accept_eula_;
+
+  content::NotificationRegistrar registrar_;

[Alexei Svitkine (slow), 2012/09/24 20:47:05]

Nit: Add a comment to mention its for the eula notifications.

[SteveT, 2012/09/24 23:30:37]

Done.

+#endif
+
+  // Observing service interested in request permissions.
+  Observer* observer_;
+
+  DISALLOW_COPY_AND_ASSIGN(ResourceRequestAllowedNotifier);
+};
+
+#endif  // CHROME_BROWSER_METRICS_VARIATIONS_RESOURCE_REQUEST_ALLOWED_NOTIFIER_H_