Add mock classes for Bus, ObjectProxy, and ExportedObject.

dbus/mock_object_proxy.cc

Index: dbus/mock_object_proxy.cc
diff --git a/dbus/mock_object_proxy.cc b/dbus/mock_object_proxy.cc
new file mode 100644
index 0000000000000000000000000000000000000000..d58a6048823c7215d9bd870157fc28dd19a09bb2
--- /dev/null
+++ b/dbus/mock_object_proxy.cc
@@ -0,0 +1,18 @@
+// 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.
+
+#include "dbus/mock_object_proxy.h"
+
+namespace dbus {
+
+MockObjectProxy::MockObjectProxy(Bus* bus,
+                                 const std::string& service_name,
+                                 const std::string& object_path)
+    : ObjectProxy(bus, service_name, object_path) {
+}
+
+MockObjectProxy::~MockObjectProxy() {
+}
+
+}  // namespace dbus