Move app_launcher.* out of chrome/browser/extensions and into apps/

chrome/browser/extensions/app_launcher.h

-// Copyright (c) 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_EXTENSIONS_APP_LAUNCHER_H_
-#define CHROME_BROWSER_EXTENSIONS_APP_LAUNCHER_H_
-
-#include "base/basictypes.h"
-#include "base/callback_forward.h"
-
-class PrefRegistrySimple;
-
-namespace extensions {
-
-// Called on the UI thread after determining if the launcher is enabled. A
-// boolean flag is passed, which is true if the app launcher is enabled.
-typedef base::Callback<void(bool)> OnAppLauncherEnabledCompleted;
-
-// Determine whether the app launcher is enabled or not. This may involve a trip
-// to a blocking thread. |completion_callback| is called when an answer is
-// ready. This needs to be called on the UI thread.
-void UpdateIsAppLauncherEnabled(
-    const OnAppLauncherEnabledCompleted& completion_callback);
-
-// returns value of pref. 'was app launcher enabled last time i checked'.
-bool IsAppLauncherEnabled();
-
-namespace app_launcher {
-void RegisterPrefs(PrefRegistrySimple* registry);
-}
-
-}  // namespace extensions
-
-#endif  // CHROME_BROWSER_EXTENSIONS_APP_LAUNCHER_H_