Promotes Add/RemoveObserver to MessageLoop for linux. Because...

base/base.gyp

 # Copyright (c) 2009 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': [
     '../build/common.gypi',
@@ skipping 413 matching lines @@
             ],
             'cflags': [
               '-Wno-write-strings',
             ],
             'link_settings': {
               'libraries': [
                 # We need rt for clock_gettime().
                 '-lrt',
               ],
             },
+            'export_dependent_settings': [
+              '../build/linux/system.gyp:gtk',
+            ],
           },
           {  # else: OS != "linux"
             'sources/': [
               ['exclude', '/xdg_mime/'],
             ],
             'sources!': [
               'crypto/signature_verifier_nss.cc',
               'atomicops_internals_x86_gcc.cc',
               'directory_watcher_inotify.cc',
               'hmac_nss.cc',
@@ skipping 309 matching lines @@
           'target_name': 'debug_message',
           'type': 'executable',
           'sources': [
             'debug_message.cc',
           ],
         },
       ],
     }],
   ],
 }