Move app.window API implementation to extensions

extensions/common/api/app_window.idl

 // Copyright (c) 2012 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.
 
 // Use the <code>chrome.app.window</code> API to create windows. Windows
 // have an optional frame with title bar and size controls. They are not
 // associated with any Chrome browser windows. See the <a
 // href="https://github.com/GoogleChrome/chrome-app-samples/tree/master/window-state">
 // Window State Sample</a> for a demonstration of these options.
 namespace app.window {
@@ skipping 440 matching lines @@
     // Fired when the window is restored from being minimized or maximized.
     [nocompile] static void onRestored();
 
     // Fired when the window's ability to use alpha transparency changes.
     [nocompile, nodoc] static void onAlphaEnabledChanged();
 
     // Event for testing. Lets tests wait until a window has been shown.
     [nocompile, nodoc] static void onWindowFirstShown();
   };
 };