Remove unused thread.h include in trace_event_impl.h and fix IWUU.

ui/events/ozone/device/udev/device_manager_udev.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/ozone/device/udev/device_manager_udev.h"
 
 #include <stddef.h>
 
 #include "base/macros.h"
 #include "base/memory/ptr_util.h"
+#include "base/message_loop/message_loop.h"
 #include "base/strings/stringprintf.h"
 #include "base/trace_event/trace_event.h"
 #include "ui/events/ozone/device/device_event.h"
 #include "ui/events/ozone/device/device_event_observer.h"
 
 namespace ui {
 
 namespace {
 
 const char* const kSubsystems[] = {
@@ skipping 163 matching lines @@
   else if (!strcmp(action, "change"))
     action_type = DeviceEvent::CHANGE;
   else
     return nullptr;
 
   return base::MakeUnique<DeviceEvent>(device_type, action_type,
                                        base::FilePath(path));
 }
 
 }  // namespace ui