[mojo-edk] Revert ObserveProxy retransmission behavior

mojo/edk/system/ports/node.h

 // Copyright 2016 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.
 
 #ifndef MOJO_EDK_SYSTEM_PORTS_NODE_H_
 #define MOJO_EDK_SYSTEM_PORTS_NODE_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 30 matching lines @@
 struct PortStatus {
   bool has_messages;
   bool receiving_messages;
   bool peer_closed;
 };
 
 class NodeDelegate;
 
 class Node {
  public:
+  enum class ShutdownPolicy {
+    DONT_ALLOW_LOCAL_PORTS,
+    ALLOW_LOCAL_PORTS,
+  };
+
   // Does not take ownership of the delegate.
   Node(const NodeName& name, NodeDelegate* delegate);
   ~Node();
 
   // Returns true iff there are no open ports referring to another node or ports
   // in the process of being transferred from this node to another. If this
   // returns false, then to ensure clean shutdown, it is necessary to keep the
   // node alive and continue routing messages to it via AcceptMessage. This
   // method may be called again after AcceptMessage to check if the Node is now
   // ready to be destroyed.
   //
-  // If |allow_local_ports| is |true|, this will only return |false| when there
-  // are transient ports referring to other nodes.
-  bool CanShutdownCleanly(bool allow_local_ports);
+  // If |policy| is set to |ShutdownPolicy::ALLOW_LOCAL_PORTS|, this will return
+  // |true| even if some ports remain alive, as long as none of them are proxies
+  // to another node.
+  bool CanShutdownCleanly(
+      ShutdownPolicy policy = ShutdownPolicy::DONT_ALLOW_LOCAL_PORTS);
 
   // Lookup the named port.
   int GetPort(const PortName& port_name, PortRef* port_ref);
 
   // Creates a port on this node. Before the port can be used, it must be
   // initialized using InitializePort. This method is useful for bootstrapping
   // a connection between two nodes. Generally, ports are created using
   // CreatePortPair instead.
   int CreateUninitializedPort(PortRef* port_ref);
 
@@ skipping 138 matching lines @@
   std::unordered_map<PortName, scoped_refptr<Port>> ports_;
 
   DISALLOW_COPY_AND_ASSIGN(Node);
 };
 
 }  // namespace ports
 }  // namespace edk
 }  // namespace mojo
 
 #endif  // MOJO_EDK_SYSTEM_PORTS_NODE_H_