Add Mojo IPC based input-device service.

components/input_device_service/input_device_server.h

Index: components/input_device_service/input_device_server.h
diff --git a/components/input_device_service/input_device_server.h b/components/input_device_service/input_device_server.h
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+// Copyright 2016 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 COMPONENTS_INPUT_DEVICE_SERVICE_INPUT_DEVICE_SERVER_H_
+#define COMPONENTS_INPUT_DEVICE_SERVICE_INPUT_DEVICE_SERVER_H_
+
+#include "base/macros.h"
+#include "components/input_device_service/input_device_service.mojom.h"
+#include "mojo/public/cpp/bindings/binding_set.h"
+#include "mojo/public/cpp/bindings/interface_ptr_set.h"
+#include "services/shell/public/cpp/connection.h"
+#include "services/shell/public/cpp/interface_factory.h"
+#include "ui/events/devices/input_device_event_observer.h"
+
+namespace input_device {
+
+// Acts as an intermediate, listening to DeviceDataManager for updates on input
+// devices and forwards those updates via Mojo IPC to any InputDeviceClients
+// in different processes that are registered as observers.
+class InputDeviceServer
+    : public shell::InterfaceFactory<mojom::InputDeviceService>,
+      public mojom::InputDeviceService,
+      public ui::InputDeviceEventObserver {
+ public:
+  InputDeviceServer();
+  ~InputDeviceServer() override;
+
+  // Registers as an observer with DeviceDataManager.
+  void RegisterAsObserver();
+
+  // Registers mojo interfaces with shell connection.
+  void RegisterInterface(shell::Connection* connection);
+
+  // mojo::InterfaceFactory<mojom::InputDeviceService>:
+  void Create(shell::Connection* connection,
+              mojom::InputDeviceServiceRequest request) override;
+
+  // mojom::InputDeviceService:
+  void AddObserver(mojom::InputDeviceObserverPtr observer) override;
+
+  void GetKeyboardDevices(const GetKeyboardDevicesCallback& callback) override;
+  void GetTouchscreenDevices(
+      const GetTouchscreenDevicesCallback& callback) override;
+  void GetMouseDevices(const GetMouseDevicesCallback& callback) override;
+  void GetTouchpadDevices(const GetTouchpadDevicesCallback& callback) override;
+
+  // ui::InputDeviceEventObserver:
+  void OnKeyboardDeviceConfigurationChanged() override;
+  void OnTouchscreenDeviceConfigurationChanged() override;
+  void OnMouseDeviceConfigurationChanged() override;
+  void OnTouchpadDeviceConfigurationChanged() override;
+
+ private:
+  mojo::BindingSet<mojom::InputDeviceService> bindings_;
+  mojo::InterfacePtrSet<mojom::InputDeviceObserver> observers_;
+
+  // Are we registered as an observer with DeviceDataManager.
+  bool is_observing_ = false;
+
+  DISALLOW_COPY_AND_ASSIGN(InputDeviceServer);
+};
+
+}  // namespace input_device
+
+#endif  // COMPONENTS_INPUT_DEVICE_SERVICE_INPUT_DEVICE_SERVER_H_