Add SendSignalWithNoArgumentsToSystemBus() to dbus.h

chromeos/dbus/dbus.cc

 // Copyright (c) 2009 The Chromium OS 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 "chromeos/dbus/dbus.h"
 
 #include <dbus/dbus.h>
 #include <dbus/dbus-glib-bindings.h>
 #include <dbus/dbus-glib-lowlevel.h>
 #include <base/logging.h>
@@ skipping 214 matching lines @@
     return false;
   }
 
   // Determine a path from the service name and register the object.
   dbus_g_connection_register_g_object(connection.g_connection(),
                                       service_path,
                                       object);
   return true;
 }
 
-
+void SendSignalWithNoArgumentsToSystemBus(const char* path,
+                                          const char* interface_name,
+                                          const char* signal_name) {
+  CHECK(path);
+  CHECK(interface_name);
+  CHECK(signal_name);
+  chromeos::dbus::Proxy proxy(chromeos::dbus::GetSystemBusConnection(),
+                              path,
+                              interface_name);
+  DBusMessage* signal = ::dbus_message_new_signal(
+      path,
+      interface_name,
+      signal_name);
+  if (!signal) {
+    LOG(ERROR) << "Failed to create a signal: "
+               << "path: " << path << ", "
+               << "interface_name: " << interface_name << ", "
+               << "signal_name: " << signal_name;
+    return;
+  }
+  ::dbus_g_proxy_send(proxy.gproxy(), signal, NULL);
+  ::dbus_message_unref(signal);
+}
 
 }  // namespace dbus
 }  // namespace chromeos