VM: [Kernel] Revert changes to the native ports that introduced peers.

runtime/include/dart_native_api.h

Index: runtime/include/dart_native_api.h
diff --git a/runtime/include/dart_native_api.h b/runtime/include/dart_native_api.h
index 12b1b1e05ae17072246a0c79f5203e5c4aa92624..fd0e0fb4dc1e8332cc13097cdb1b9d818535a008 100644
--- a/runtime/include/dart_native_api.h
+++ b/runtime/include/dart_native_api.h
@@ -124,8 +124,7 @@ DART_EXPORT bool Dart_PostInteger(Dart_Port port_id, int64_t message);
  */
 
 typedef void (*Dart_NativeMessageHandler)(Dart_Port dest_port_id,
-                                          Dart_CObject* message,
-                                          void* peer);
+                                          Dart_CObject* message);
 
 /**
  * Creates a new native port.  When messages are received on this
@@ -136,16 +135,13 @@ typedef void (*Dart_NativeMessageHandler)(Dart_Port dest_port_id,
  * \param handler The C handler to run when messages arrive on the port.
  * \param handle_concurrently Is it okay to process requests on this
  *                            native port concurrently?
- * \param peer Peer associated with this port. It will be passed down to the
-               handler when new message arrives.
  *
  * \return If successful, returns the port id for the native port.  In
  *   case of error, returns ILLEGAL_PORT.
  */
 DART_EXPORT Dart_Port Dart_NewNativePort(const char* name,
                                          Dart_NativeMessageHandler handler,
-                                         bool handle_concurrently,
-                                         void* peer);
+                                         bool handle_concurrently);
 /* TODO(turnidge): Currently handle_concurrently is ignored. */
 
 /**