Remove unused class ShellAppWindowController

extensions/shell/app_shell.gyp

 # 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.
 
 {
   'variables': {
     'chromium_code': 1,
   },
   'targets': [
     {
@@ skipping 42 matching lines @@
         'browser/default_shell_browser_main_delegate.cc',
         'browser/default_shell_browser_main_delegate.h',
         'browser/desktop_controller.cc',
         'browser/desktop_controller.h',
         'browser/media_capture_util.cc',
         'browser/media_capture_util.h',
         'browser/shell_app_delegate.cc',
         'browser/shell_app_delegate.h',
         'browser/shell_app_window.cc',
         'browser/shell_app_window.h',
-        'browser/shell_app_window_controller.h',
         'browser/shell_apps_client.cc',
         'browser/shell_apps_client.h',
         'browser/shell_audio_controller_chromeos.cc',
         'browser/shell_audio_controller_chromeos.h',
         'browser/shell_browser_context.cc',
         'browser/shell_browser_context.h',
         'browser/shell_browser_main_delegate.h',
         'browser/shell_browser_main_parts.cc',
         'browser/shell_browser_main_parts.h',
         'browser/shell_content_browser_client.cc',
@@ skipping 192 matching lines @@
             '<@(_outputs)',
           ],
           'includes': [
             '../../build/util/version.gypi',
           ],
         },
       ],
     },
   ],  # targets
 }