Revert "- Make ports be less predictable."

runtime/vm/port.h

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_PORT_H_
 #define VM_PORT_H_
 
 #include "include/dart_api.h"
 #include "vm/allocation.h"
 #include "vm/globals.h"
-#include "vm/random.h"
 
 namespace dart {
 
 class Isolate;
 class Message;
 class MessageHandler;
 class Mutex;
 class PortMapTestPeer;
 
 class PortMap: public AllStatic {
@@ skipping 54 matching lines @@
   // Lock protecting access to the port map.
   static Mutex* mutex_;
 
   // Hashmap of ports.
   static Entry* map_;
   static MessageHandler* deleted_entry_;
   static intptr_t capacity_;
   static intptr_t used_;
   static intptr_t deleted_;
 
-  static Random* prng_;
+  static Dart_Port next_port_;
 };
 
 }  // namespace dart
 
 #endif  // VM_PORT_H_