Add libdbus dependency for Linux.

build/linux/system.gyp

 # 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.
 
 {
   'conditions': [
     ['sysroot!=""', {
       'variables': {
         'pkg-config': './pkg-config-wrapper "<(sysroot)"',
       },
@@ skipping 394 matching lines @@
               '<!@(<(pkg-config) --libs-only-L --libs-only-other gnome-keyring-1)',
             ],
             'libraries': [
               '<!@(<(pkg-config) --libs-only-l gnome-keyring-1)',
             ],
           },
         }],
       ],
     },
     {
+      'target_name': 'dbus',
+      'type': 'settings',
+      'direct_dependent_settings': {
+        'cflags': [
+          '<!@(<(pkg-config) --cflags dbus-1)',
+        ],
+      },
+      'link_settings': {
+        'ldflags': [
+          '<!@(<(pkg-config) --libs-only-L --libs-only-other dbus-1)',
+        ],
+        'libraries': [
+          '<!@(<(pkg-config) --libs-only-l dbus-1)',
+        ],
+      },
+    },
+    {
+      # TODO(satorux): Remove this once dbus-glib clients are gone.
       'target_name': 'dbus-glib',
       'type': 'settings',
       'direct_dependent_settings': {
         'cflags': [
           '<!@(<(pkg-config) --cflags dbus-glib-1)',
         ],
       },
       'link_settings': {
         'ldflags': [
           '<!@(<(pkg-config) --libs-only-L --libs-only-other dbus-glib-1)',
@@ skipping 32 matching lines @@
             ],
             'libraries': [
               '<!@(<(pkg-config) --libs-only-l "ibus-1.0 >= <(ibus_min_version)")',
             ],
           },
         }],
       ],
     },
   ],
 }