mus: Forward user activity from window server to detector.

ui/aura/mus/user_activity_forwarder.h

Index: ui/aura/mus/user_activity_forwarder.h
diff --git a/ui/aura/mus/user_activity_forwarder.h b/ui/aura/mus/user_activity_forwarder.h
new file mode 100644
index 0000000000000000000000000000000000000000..d1890424b88865ad0ec7be03a6ba36f3760e07bb
--- /dev/null
+++ b/ui/aura/mus/user_activity_forwarder.h
@@ -0,0 +1,47 @@
+// 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 UI_AURA_MUS_USER_ACTIVITY_FORWARDER_H_
+#define UI_AURA_MUS_USER_ACTIVITY_FORWARDER_H_
+
+#include "base/compiler_specific.h"
+#include "base/macros.h"
+#include "mojo/public/cpp/bindings/binding.h"
+#include "services/ui/public/interfaces/user_activity_monitor.mojom.h"
+#include "ui/aura/aura_export.h"
+
+namespace ui {
+class UserActivityDetector;
+}
+
+namespace aura {
+
+// Helper class that receives reports of user activity from the mojo
+// UserActivityMonitor interface (in the window server) and forwards them to
+// ui::UserActivityDetector (usually in ash).
+// TODO(derat): Make current ui::UserActivityObserver implementations (i.e.
+// downstream of ui::UserActivityDetector) instead observe UserActivityMonitor
+// directly: http://crbug.com/626899
+class AURA_EXPORT UserActivityForwarder
+    : NON_EXPORTED_BASE(public ui::mojom::UserActivityObserver) {
+ public:
+  UserActivityForwarder(ui::mojom::UserActivityMonitorPtr monitor,
+                        ui::UserActivityDetector* detector);
+  ~UserActivityForwarder() override;
+
+ private:
+  // ui::mojom::UserActivityObserver:
+  void OnUserActivity() override;
+
+  ui::mojom::UserActivityMonitorPtr monitor_;
+  mojo::Binding<ui::mojom::UserActivityObserver> binding_;
+
+  ui::UserActivityDetector* detector_;  // Not owned.
+
+  DISALLOW_COPY_AND_ASSIGN(UserActivityForwarder);
+};
+
+}  // namespace aura
+
+#endif  // UI_AURA_MUS_USER_ACTIVITY_FORWARDER_H_