Make CapabilityFilter non-nullable.

mojo/application/public/interfaces/shell.mojom

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 module mojo;
 
 import "mojo/application/public/interfaces/service_provider.mojom";
 import "network/public/interfaces/url_loader.mojom";
 
 // Specifies a whitelist of applications and services an application can connect
@@ skipping 38 matching lines @@
   // At least one of |services| or |exposed_services| should be valid/bound in
   // the call.
   //
   // If the |application_url| does not contain a domain, but is of the form
   // "mojo:{service}", it is up to the Mojo shell to select an appropriate
   // application for the service. Currently, the shell does this based on the
   // value of its --origin flag.
   //
   // |filter| is a whitelist of application URLs and services that the target
   // application is permitted to connect to. See documentation for
-  // CapabilityFilter above. Note also that this parameter may be NULL, which
-  // has the same meaning as allowing the target application to connect to
-  // any application and service.
+  // CapabilityFilter above.
   //
   // If the connection to |application_url| involves a content handler, then
   // |content_handler_id| is the id of the deepest content handler used to
   // establish the connection to |application_url|. If no content handler is
   // used |content_handler_id| is kInvalidContentHandlerID.
   // TODO(beng): determine if we need to expose the target application id also.
   ConnectToApplication(URLRequest application_url,
                        ServiceProvider&? services,
                        ServiceProvider? exposed_services,
-                       CapabilityFilter? filter) => (uint32 content_handler_id);
+                       CapabilityFilter filter) => (uint32 content_handler_id);
 
   // When there are no more instantiated services in an application, it should
   // start its shutdown process by calling this method. Additionally, it should
   // keep track of any new service requests that come in. The shell will then
   // call Application::OnQuitRequested and start queueing new service requests.
   // If the application didn't get any new service requests in the meantime, it
   // should call the callback with a true value. Otherwise it should call it
   // with false.
   QuitApplication();
 };