chromeos: Move files in //ash/common to //ash, part 3

ash/common/key_event_watcher.cc

-// Copyright 2016 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 "ash/common/key_event_watcher.h"
-
-namespace ash {
-
-KeyEventWatcher::KeyEventWatcher() {}
-
-KeyEventWatcher::~KeyEventWatcher() {}
-
-void KeyEventWatcher::AddKeyEventCallback(const ui::Accelerator& key,
-                                          const KeyEventCallback& callback) {
-  callback_map_.insert(std::make_pair(key, callback));
-}
-
-bool KeyEventWatcher::HandleKeyEvent(const ui::KeyEvent& event) {
-  auto iter = callback_map_.find(ui::Accelerator(event));
-  if (iter != callback_map_.end()) {
-    iter->second.Run(event);
-    return true;
-  }
-  return false;
-}
-
-}  // namespace ash