Add libdbus dependency for Linux.

dbus/dbus.gyp

Index: dbus/dbus.gyp
diff --git a/dbus/dbus.gyp b/dbus/dbus.gyp
new file mode 100644
index 0000000000000000000000000000000000000000..f2f842b3ef14220e19a0008a6a5d65da55efe689
--- /dev/null
+++ b/dbus/dbus.gyp
@@ -0,0 +1,21 @@
+# 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.
+
+{
+  'variables': {
+    'chromium_code': 1,
+  },
+  'targets': [
+    {
+      'target_name': 'dbus',
+      'type': 'static_library',
+      'dependencies': [
+        '../base/base.gyp:base',
+        '../build/linux/system.gyp:dbus',
+      ],
+      'sources': [
+      ],
+    },
+  ],
+}