Add Mojo IPC based input-device service.

ui/events/devices/input_device.h

 // Copyright 2014 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_EVENTS_DEVICES_INPUT_DEVICE_H_
 #define UI_EVENTS_DEVICES_INPUT_DEVICE_H_
 
 #include <stdint.h>
 #include <string>
 
@@ skipping 18 matching lines @@
   InputDevice(int id, InputDeviceType type, const std::string& name);
   InputDevice(int id,
               InputDeviceType type,
               const std::string& name,
               const base::FilePath& sys_path,
               uint16_t vendor,
               uint16_t product);
   InputDevice(const InputDevice& other);
   virtual ~InputDevice();
 
+  std::string ToString() const;
+
   // ID of the device. This ID is unique between all input devices.
   int id;
 
   // The type of the input device.
   InputDeviceType type;
 
   // Name of the device.
   std::string name;
 
   // The path to the input device in the sysfs filesystem.
   base::FilePath sys_path;
 
   // USB-style device identifiers, where available, or 0 if unavailable.
   uint16_t vendor_id;
   uint16_t product_id;
 };
 
 }  // namespace ui
 
 #endif  // UI_EVENTS_DEVICES_INPUT_DEVICE_H_