Remove default value for argument (was missing from previous commit)

runtime/bin/process.h

 // Copyright (c) 2012, 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 BIN_PROCESS_H_
 #define BIN_PROCESS_H_
 
 #include "bin/builtin.h"
 #include "bin/io_buffer.h"
 #include "bin/thread.h"
@@ skipping 120 matching lines @@
   static int global_exit_code_;
   static dart::Mutex* global_exit_code_mutex_;
 
   DISALLOW_ALLOCATION();
   DISALLOW_IMPLICIT_CONSTRUCTORS(Process);
 };
 
 
 class SignalInfo {
  public:
-  SignalInfo(int fd, int signal, SignalInfo* next = NULL)
+  SignalInfo(int fd, int signal, SignalInfo* next)
       : fd_(fd),
         signal_(signal),
         // SignalInfo is expected to be created when in a isolate.
         port_(Dart_GetMainPortId()),
         next_(next),
         prev_(NULL) {
     if (next_ != NULL) {
       next_->prev_ = this;
     }
   }
@@ skipping 122 matching lines @@
   intptr_t data_size_;
 
   // Number of free bytes in the last node in the list.
   intptr_t free_size_;
 };
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // BIN_PROCESS_H_