Convert mojo::system::ChannelEndpointClient to use our new refcounting stuff (instead of base's).

mojo/edk/system/channel_endpoint.cc

Index: mojo/edk/system/channel_endpoint.cc
diff --git a/mojo/edk/system/channel_endpoint.cc b/mojo/edk/system/channel_endpoint.cc
index 70b803496eddbe360d9c6283e6fe6cce7adf1da0..b2ced62cf521ba0d919eb5c889e8dbb3f58af748 100644
--- a/mojo/edk/system/channel_endpoint.cc
+++ b/mojo/edk/system/channel_endpoint.cc
@@ -35,14 +35,14 @@ bool ChannelEndpoint::EnqueueMessage(
   return false;
 }
 
-bool ChannelEndpoint::ReplaceClient(ChannelEndpointClient* client,
+bool ChannelEndpoint::ReplaceClient(RefPtr<ChannelEndpointClient>&& client,
                                     unsigned client_port) {
   DCHECK(client);
 
   MutexLocker locker(&mutex_);
   DCHECK(client_);
-  DCHECK(client != client_.get() || client_port != client_port_);
-  client_ = client;
+  DCHECK(client != client_ || client_port != client_port_);
+  client_ = std::move(client);
   client_port_ = client_port;
   return state_ != State::DEAD;
 }
@@ -102,7 +102,7 @@ void ChannelEndpoint::OnReadMessage(std::unique_ptr<MessageInTransit> message) {
 }
 
 void ChannelEndpoint::DetachFromChannel() {
-  scoped_refptr<ChannelEndpointClient> client;
+  RefPtr<ChannelEndpointClient> client;
   unsigned client_port = 0;
   {
     MutexLocker locker(&mutex_);
@@ -131,11 +131,11 @@ void ChannelEndpoint::DetachFromChannel() {
     client->OnDetachFromChannel(client_port);
 }
 
-ChannelEndpoint::ChannelEndpoint(ChannelEndpointClient* client,
+ChannelEndpoint::ChannelEndpoint(RefPtr<ChannelEndpointClient>&& client,
                                  unsigned client_port,
                                  MessageInTransitQueue* message_queue)
     : state_(State::PAUSED),
-      client_(client),
+      client_(std::move(client)),
       client_port_(client_port),
       channel_(nullptr) {
   DCHECK(client_ || message_queue);
@@ -171,7 +171,7 @@ void ChannelEndpoint::OnReadMessageForClient(
     std::unique_ptr<MessageInTransit> message) {
   DCHECK_EQ(message->type(), MessageInTransit::Type::ENDPOINT_CLIENT);
 
-  scoped_refptr<ChannelEndpointClient> client;
+  RefPtr<ChannelEndpointClient> client;
   unsigned client_port = 0;
 
   // This loop is to make |ReplaceClient()| work. We can't call the client's