shill: Implement a DBusManager class to listen for name/owner notifications.

An instance of DBusManager is instantiated in Manager. It will be used to detect
DBus services appearing and disappearing and syncing properly.

BUG=chromium-os:31712
TEST=unit tests, tested on device with extra logging and pkill wpa_supplicant

Change-Id: I701d2efff405769bc14f5589331c54647b41beab
Reviewed-on: https://gerrit.chromium.org/gerrit/26014
Tested-by: Darin Petkov <petkov@chromium.org>
Reviewed-by: Ben Chan <benchan@chromium.org>
Commit-Ready: Darin Petkov <petkov@chromium.org>
diff --git a/dbus_service_proxy.cc b/dbus_service_proxy.cc
index c12e721..fb82c3e 100644
--- a/dbus_service_proxy.cc
+++ b/dbus_service_proxy.cc
@@ -52,7 +52,7 @@
 
 DBusServiceProxy::Proxy::Proxy(DBus::Connection *connection)
     : DBus::ObjectProxy(*connection,
-                        dbus::kDBusServiceName, dbus::kDBusServicePath) {}
+                        dbus::kDBusServicePath, dbus::kDBusServiceName) {}
 
 DBusServiceProxy::Proxy::~Proxy() {}