Add |native_bridge_experiment| to arc.proto
am: bb5e81cbae

Change-Id: Ia25211588c2f4786dfd51816d13b97bd32971926
diff --git a/dbus/login_manager/arc.proto b/dbus/login_manager/arc.proto
index 47e992f..5d4893e 100644
--- a/dbus/login_manager/arc.proto
+++ b/dbus/login_manager/arc.proto
@@ -33,5 +33,8 @@
   // TODO(yusukes): Make this always enabled and then remove the field.
   optional bool create_server_socket = 5;
 
-  // Next ID to use: 6
+  // Option to enable native bridge experiment (b/63133475).
+  optional bool native_bridge_experiment = 6;
+
+  // Next ID to use: 7
 }