Support custom message filtering on Mojo binding objects

mojo/public/cpp/bindings/lib/router.cc

 // 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.
 
 #include "mojo/public/cpp/bindings/lib/router.h"
 
 #include <stdint.h>
 
 #include <utility>
 
@@ skipping 115 matching lines @@
                  std::move(runner)),
       incoming_receiver_(nullptr),
       next_request_id_(0),
       testing_mode_(false),
       pending_task_for_messages_(false),
       encountered_error_(false),
       weak_factory_(this) {
   filters_.SetSink(&thunk_);
   if (expects_sync_requests)
     connector_.AllowWokenUpBySyncWatchOnSameThread();
-  connector_.set_incoming_receiver(filters_.GetHead());
+  connector_.set_incoming_receiver(&filters_);
   connector_.set_connection_error_handler(
       base::Bind(&Router::OnConnectionError, base::Unretained(this)));
 }
 
 Router::~Router() {}
 
+void Router::AddFilter(std::unique_ptr<MessageReceiver> filter) {
+  filters_.Append(std::move(filter));
+}
+
 bool Router::Accept(Message* message) {
   DCHECK(thread_checker_.CalledOnValidThread());
   DCHECK(!message->has_flag(Message::kFlagExpectsResponse));
   return connector_.Accept(message);
 }
 
 bool Router::AcceptWithResponder(Message* message, MessageReceiver* responder) {
   DCHECK(thread_checker_.CalledOnValidThread());
   DCHECK(message->has_flag(Message::kFlagExpectsResponse));
 
@@ skipping 163 matching lines @@
   async_responders_.clear();
 
   if (!error_handler_.is_null())
     error_handler_.Run();
 }
 
 // ----------------------------------------------------------------------------
 
 }  // namespace internal
 }  // namespace mojo