Extracted shell_interfaces and shell_public into a separate gyp file.

content/content_utility.gypi

 # Copyright (c) 2011 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.
 
 {
   'dependencies': [
     '../base/base.gyp:base',
     '../courgette/courgette.gyp:courgette_lib',
     '../mojo/mojo_base.gyp:mojo_common_lib',
     '../mojo/mojo_public.gyp:mojo_cpp_bindings',
-    '../services/shell/shell.gyp:shell_public',
     '../services/shell/shell.gyp:shell_lib',
+    '../services/shell/shell_public.gyp:shell_public',
     '../url/url.gyp:url_lib',
   ],
   'variables': {
     'utility_sources': [
       'utility/in_process_utility_thread.cc',
       'utility/in_process_utility_thread.h',
       'utility/utility_blink_platform_impl.cc',
       'utility/utility_blink_platform_impl.h',
       'utility/utility_main.cc',
       'utility/utility_process_control_impl.cc',
@@ skipping 11 matching lines @@
     ],
   },
   'include_dirs': [
     '..',
   ],
   'sources': [
     '<@(public_utility_sources)',
     '<@(utility_sources)',
   ],
 }