Mojo: Remove unused hello_world_service code

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.
 
 {
   'variables': {
     'chromium_code': 1,
   },
   'includes': [
     'mojo_apps.gypi',
     'mojo_examples.gypi',
     'mojo_public.gypi',
     'mojo_services.gypi',
   ],
   'targets': [
     {
       'target_name': 'mojo',
       'type': 'none',
       'dependencies': [
         'mojo_bindings',
         'mojo_bindings_unittests',
         'mojo_common_lib',
         'mojo_common_unittests',
-        'mojo_hello_world_service',
         'mojo_js',
         'mojo_js_unittests',
         'mojo_public_perftests',
         'mojo_public_test_support',
         'mojo_public_unittests',
         'mojo_sample_app',
         'mojo_shell',
         'mojo_shell_lib',
         'mojo_shell_unittests',
         'mojo_system',
@@ skipping 375 matching lines @@
             'java_in_dir': '<(DEPTH)/mojo/shell/android/apk',
             'resource_dir': '<(DEPTH)/mojo/shell/android/apk/res',
             'native_lib_target': 'libmojo_shell',
           },
           'includes': [ '../build/java_apk.gypi' ],
         }
       ],
     }],
   ],
 }