Make PointerDeviceObserver work under Ozone

ui/events/platform/x11/x11_hotplug_event_handler.cc

 // 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.
 
 #include "ui/events/platform/x11/x11_hotplug_event_handler.h"
 
 #include <X11/Xatom.h>
 #include <X11/extensions/XInput.h>
 #include <X11/extensions/XInput2.h>
 
@@ skipping 322 matching lines @@
   }
 
   // X11 is not thread safe, so first get all the required state.
   DisplayState display_state;
   display_state.mt_position_x = atom_cache_.GetAtom("Abs MT Position X");
   display_state.mt_position_y = atom_cache_.GetAtom("Abs MT Position Y");
 
   UiCallbacks callbacks;
   callbacks.keyboard_callback = base::Bind(&OnKeyboardDevices);
   callbacks.touchscreen_callback = base::Bind(&OnTouchscreenDevices);
+  // TODO(pkotwicz): Compute the lists of mice and touchpads and send the new
+  // lists to DeviceHotplugEventObserver.
 
   // Parsing the device information may block, so delegate the operation to a
   // worker thread. Once the device information is extracted the parsed devices
   // will be returned via the callbacks.
   base::WorkerPool::PostTask(FROM_HERE,
                              base::Bind(&HandleHotplugEventInWorker,
                                         device_infos,
                                         display_state,
                                         base::ThreadTaskRunnerHandle::Get(),
                                         callbacks),
                              true /* task_is_slow */);
 }
 
 }  // namespace ui