Reject all callbacks with DeviceLost on wire client disconnect

When the wire is disconnected, the client will not receive any
messages from the server. We need to manually reject all callbacks.

Bug: dawn:556
Change-Id: Ia03456b3209dbe0e1e54543d344180d11d4c6f1e
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/31162
Commit-Queue: Austin Eng <enga@chromium.org>
Reviewed-by: Stephen White <senorblanco@chromium.org>

generator/templates/dawn_wire/client/ApiObjects.h

@@ -28,7 +28,7 @@ namespace dawn_wire { namespace client {
         {% if type.name.CamelCase() in client_special_objects %}
             class {{Type}};
         {% else %}
-            struct {{type.name.CamelCase()}} : ObjectBase {
+            struct {{type.name.CamelCase()}} final : ObjectBase {
                 using ObjectBase::ObjectBase;
             };
         {% endif %}