Add support for logging information about mojo messages retrieved by the mojo debugger

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 455 matching lines @@
       'target_name': 'mojo_spy',
       'type': 'static_library',
       'dependencies': [
         '../base/base.gyp:base',
         '../base/base.gyp:base_static',
         '../net/net.gyp:http_server',
         '../url/url.gyp:url_lib',
         'mojo_service_manager',
       ],
       'sources': [
+        'spy/common.h',
         'spy/spy.cc',
         'spy/spy.h',
         'spy/websocket_server.cc',
         'spy/websocket_server.h',
       ],
     },
     {
       'target_name': 'mojo_shell_lib',
       'type': 'static_library',
       'dependencies': [
@@ skipping 505 matching lines @@
             'views/views_init_internal.h',
           ],
           'defines': [
             'MOJO_VIEWS_IMPLEMENTATION',
           ],
         },
       ],
     }],
   ],
 }