Get rid of KeepAlive. Quit shell when all urls run directly by Context are closed.

mojo/mojo.gyp

 # Copyright 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.
 
 {
   'target_defaults': {
     'conditions': [
       ['mojo_shell_debug_url != ""', {
         'defines': [
           'MOJO_SHELL_DEBUG=1',
@@ skipping 154 matching lines @@
         'shell/context.h',
         'shell/dbus_application_loader_linux.cc',
         'shell/dbus_application_loader_linux.h',
         'shell/dynamic_application_loader.cc',
         'shell/dynamic_application_loader.h',
         'shell/dynamic_service_runner.h',
         'shell/init.cc',
         'shell/init.h',
         'shell/in_process_dynamic_service_runner.cc',
         'shell/in_process_dynamic_service_runner.h',
-        'shell/keep_alive.cc',
-        'shell/keep_alive.h',
         'shell/mojo_url_resolver.cc',
         'shell/mojo_url_resolver.h',
         'shell/out_of_process_dynamic_service_runner.cc',
         'shell/out_of_process_dynamic_service_runner.h',
-        'shell/run.cc',
-        'shell/run.h',
         'shell/switches.cc',
         'shell/switches.h',
         'shell/task_runners.cc',
         'shell/task_runners.h',
         'shell/test_child_process.cc',
         'shell/test_child_process.h',
         'shell/ui_application_loader_android.cc',
         'shell/ui_application_loader_android.h',
         'shell/view_manager_loader.cc',
         'shell/view_manager_loader.h',
@@ skipping 333 matching lines @@
             'views/views_init_internal.h',
           ],
           'defines': [
             'MOJO_VIEWS_IMPLEMENTATION',
           ],
         },
       ],
     }],
   ],
 }