Remove app_shell chrome.shell API and ShellAppWindow

athena/content/chrome/content_activity_factory.cc

 // 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.
 
 #include "athena/content/content_activity_factory.h"
 
 #include "athena/content/app_activity.h"
 #include "extensions/browser/app_window/app_window.h"
 #include "ui/views/controls/webview/webview.h"
 
@@ skipping 35 matching lines @@
 };
 
 }  // namespace
 
 Activity* ContentActivityFactory::CreateAppActivity(
     extensions::AppWindow* app_window,
     views::WebView* web_view) {
   return new ChromeAppActivity(app_window, web_view);
 }
 
-Activity* ContentActivityFactory::CreateAppActivity(
-    extensions::ShellAppWindow* app_window,
-    const std::string& app_id) {
-  return NULL;
-}
-
 }  // namespace athena