Remove KeyboardDevice class.

ui/events/devices/device_hotplug_event_observer.h

Index: ui/events/devices/device_hotplug_event_observer.h
diff --git a/ui/events/devices/device_hotplug_event_observer.h b/ui/events/devices/device_hotplug_event_observer.h
index 1e10d28eed88042e0cc293f4890cab7d2422f53b..c0b3bc6d7ea15565dafeac783549f8c8c7481f70 100644
--- a/ui/events/devices/device_hotplug_event_observer.h
+++ b/ui/events/devices/device_hotplug_event_observer.h
@@ -12,7 +12,6 @@
 namespace ui {
 
 struct InputDevice;
-struct KeyboardDevice;
 struct TouchscreenDevice;
 
 // Listener for specific input device hotplug events.
@@ -28,7 +27,7 @@ class EVENTS_DEVICES_EXPORT DeviceHotplugEventObserver {
   // On a hotplug event this is called with the list of available keyboard
   // devices. The set of keyboard devices may not have changed.
   virtual void OnKeyboardDevicesUpdated(
-      const std::vector<KeyboardDevice>& devices) = 0;
+      const std::vector<InputDevice>& devices) = 0;
 
   // On a hotplug event this is called with the list of available mice. The set
   // of mice may not have changed.