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

mojo/edk/system/endpoint_relayer.cc

Index: mojo/edk/system/endpoint_relayer.cc
diff --git a/mojo/edk/system/endpoint_relayer.cc b/mojo/edk/system/endpoint_relayer.cc
index d1b82bec519d0b5f084bf00e3693b65dbd839c93..0cf4efa860351dcbd31ddc212a4171bb8a603c2e 100644
--- a/mojo/edk/system/endpoint_relayer.cc
+++ b/mojo/edk/system/endpoint_relayer.cc
@@ -13,9 +13,6 @@
 namespace mojo {
 namespace system {
 
-EndpointRelayer::EndpointRelayer() {
-}
-
 // static
 unsigned EndpointRelayer::GetPeerPort(unsigned port) {
   DCHECK(port == 0 || port == 1);
@@ -77,6 +74,8 @@ void EndpointRelayer::OnDetachFromChannel(unsigned port) {
   }
 }
 
+EndpointRelayer::EndpointRelayer() {}
+
 EndpointRelayer::~EndpointRelayer() {
   DCHECK(!endpoints_[0]);
   DCHECK(!endpoints_[1]);