mus: Forward user activity from window server to detector.

ash/mus/user_activity_forwarder.h

+// Copyright 2017 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 ASH_MUS_USER_ACTIVITY_FORWARDER_H_
+#define ASH_MUS_USER_ACTIVITY_FORWARDER_H_
+
+#include "base/macros.h"
+#include "mojo/public/cpp/bindings/binding.h"
+#include "services/ui/public/interfaces/user_activity_monitor.mojom.h"
+
+namespace service_manager {
+class Connector;
+}
+
+namespace ui {
+class UserActivityDetector;
+}
+
+namespace ash {
+namespace mus {
+
+// Helper class that receives reports of user activity from UserActivityMonitor
+// and forwards them to ui::UserActivityDetector.
+// TODO(derat): Make current ui::UserActivityObserver implementations (i.e.
+// downstream of ui::UserActivityDetector) instead observe UserActivityMonitor
+// directly: http://crbug.com/626899
+class UserActivityForwarder : public ui::mojom::UserActivityObserver {

[Daniel Erat, 2017/01/18 01:12:59]

a forwarder like this seems necessary since //services/ui depends on //ui,
preventing the existing UserActivityDetector class from registering from
notifications from UserActivityMonitor.

+ public:
+  UserActivityForwarder(service_manager::Connector* connector,
+                        ui::UserActivityDetector* detector);
+  ~UserActivityForwarder() override;
+
+ private:
+  // ui::mojom::UserActivityObserver:
+  void OnUserActivity();
+
+  ui::mojom::UserActivityMonitorPtr user_activity_monitor_;
+  mojo::Binding<ui::mojom::UserActivityObserver>
+      user_activity_observer_binding_;
+
+  ui::UserActivityDetector* user_activity_detector_;  // Not owned.
+
+  DISALLOW_COPY_AND_ASSIGN(UserActivityForwarder);
+};
+
+}  // namespace mus
+}  // namespace ash
+
+#endif  // ASH_MUS_USER_ACTIVITY_FORWARDER_H_