Automatically remap Command key on an Apple keyboard to Control [part 2 of 2 - Chrome part]

chrome/browser/chromeos/device_hierarchy_observer.h

 // Copyright (c) 2011 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_CHROMEOS_DEVICE_HIERARCHY_OBSERVER_H_
 #define CHROME_BROWSER_CHROMEOS_DEVICE_HIERARCHY_OBSERVER_H_
 #pragma once
 
 namespace chromeos {
 
 // Observers receive notifications when a device has been added/removed.
 class DeviceHierarchyObserver {
  public:
   virtual void DeviceHierarchyChanged() = 0;
 
+  // Called when a new device (e.g. an external USB keyboard) is attached.
+  virtual void DeviceAdded(int device_id) = 0;
+
+  // Called when a key either on a built-in keyboard or external one is pressed.
+  // |device_id| is the source of the key event which will be sent to the Chrome
+  // window shortly.
+  virtual void KeyPressedOrReleased(int device_id) = 0;
+
  protected:
   virtual ~DeviceHierarchyObserver() {}
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_DEVICE_HIERARCHY_OBSERVER_H_