Remove base/win/metro.{cc|h} and some associated code

chrome/browser/metro_utils/metro_chrome_win.h

-// Copyright 2013 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_METRO_UTILS_METRO_CHROME_WIN_H_
-#define CHROME_BROWSER_METRO_UTILS_METRO_CHROME_WIN_H_
-
-#include "chrome/browser/ui/host_desktop.h"
-
-namespace chrome {
-
-// Using IApplicationActivationManager::ActivateApplication, activate the
-// Chrome window running in Metro mode. Returns true if the activation was
-// successful. Note that this can not be called nested in another COM
-// SendMessage (results in error RPC_E_CANTCALLOUT_ININPUTSYNCCALL), so use
-// PostTask to handle that case.
-bool ActivateMetroChrome();
-
-enum Win8Environment {
-  WIN_8_ENVIRONMENT_METRO_AURA,
-  WIN_8_ENVIRONMENT_DESKTOP_AURA,
-  WIN_8_ENVIRONMENT_MAX
-};
-
-Win8Environment GetWin8Environment(HostDesktopType desktop);
-
-}  // namespace chrome
-
-#endif  // CHROME_BROWSER_METRO_UTILS_METRO_CHROME_WIN_H_