Make client use binder interface on brillo

TEST=Verified status and update commands
Bug: 25908638

Change-Id: I7994de41001b4e116bffa539f23f1344ab1deae9
diff --git a/client_library/client_dbus.cc b/client_library/client_dbus.cc
index 0d02936..d9b4a05 100644
--- a/client_library/client_dbus.cc
+++ b/client_library/client_dbus.cc
@@ -159,20 +159,20 @@
       last_checked_time, progress, status, new_version, new_size);
 }
 
-void DBusUpdateEngineClient::RegisterStatusUpdateHandler(
+bool DBusUpdateEngineClient::RegisterStatusUpdateHandler(
     StatusUpdateHandler* handler) {
   if (!base::MessageLoopForIO::current()) {
     LOG(FATAL) << "Cannot get UpdateEngineClient outside of message loop.";
-    return;
+    return false;
   }
 
   proxy_->RegisterStatusUpdateSignalHandler(
       base::Bind(&DBusUpdateEngineClient::RunStatusUpdateHandler,
-                 base::Unretained(this),
-                 base::Unretained(handler)),
+                 base::Unretained(this), base::Unretained(handler)),
       base::Bind(&DBusUpdateEngineClient::StatusUpdateHandlerRegistered,
-                 base::Unretained(this),
-                 base::Unretained(handler)));
+                 base::Unretained(this), base::Unretained(handler)));
+
+  return true;
 }
 
 bool DBusUpdateEngineClient::SetTargetChannel(const string& in_target_channel,