Add the ability to load multiple apps into app_shell.

athena/main/athena_main.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/activity/public/activity_factory.h"
 #include "athena/activity/public/activity_manager.h"
 #include "athena/content/public/web_contents_view_delegate_creator.h"
 #include "athena/env/public/athena_env.h"
 #include "athena/extensions/public/extensions_delegate.h"
 #include "athena/main/athena_content_client.h"
@@ skipping 51 matching lines @@
       const extensions::Extension* extension) override {
     NOTIMPLEMENTED();
     return NULL;
   }
 
   // Adds the window to the desktop.
   virtual void AddAppWindow(aura::Window* window) override {
     NOTIMPLEMENTED();
   }
 
+  virtual void RemoveAppWindow(extensions::AppWindow* window) override {}
+
   // Closes and destroys the app windows.
   virtual void CloseAppWindows() override {}
 
   DISALLOW_COPY_AND_ASSIGN(AthenaDesktopController);
 };
 
 class AthenaBrowserMainDelegate : public extensions::ShellBrowserMainDelegate {
  public:
   AthenaBrowserMainDelegate() {}
   virtual ~AthenaBrowserMainDelegate() {}
@@ skipping 108 matching lines @@
 
 int main(int argc, const char** argv) {
   AthenaMainDelegate delegate;
   content::ContentMainParams params(&delegate);
 
   params.argc = argc;
   params.argv = argv;
 
   return content::ContentMain(params);
 }