[mojo] Implement pipe fusion API

mojo/edk/system/node_controller.cc

Index: mojo/edk/system/node_controller.cc
diff --git a/mojo/edk/system/node_controller.cc b/mojo/edk/system/node_controller.cc
index 4849806c027bd49c13620933963c3d4e5392fad2..1472f03fd5a161e867f45409b6fe32b0a23e60e4 100644
--- a/mojo/edk/system/node_controller.cc
+++ b/mojo/edk/system/node_controller.cc
@@ -209,6 +209,13 @@ void NodeController::MergePortIntoParent(const std::string& token,
   parent->RequestPortMerge(port.name(), token);
 }
 
+int NodeController::MergeLocalPorts(const ports::PortRef& port0,
+                                    const ports::PortRef& port1) {
+  int rv = node_->MergeLocalPorts(port0, port1);
+  AcceptIncomingMessages();
+  return rv;
+}
+
 scoped_refptr<PlatformSharedBuffer> NodeController::CreateSharedBuffer(
     size_t num_bytes) {
   // TODO(amistry): Fix sync broker and re-enable on OSX.