Introduce optional 'bool shared' parameter to ServerSocket.bind() ...

dart/runtime/bin/eventhandler_macos.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_EVENTHANDLER_MACOS_H_
 #define BIN_EVENTHANDLER_MACOS_H_
 
 #if !defined(BIN_EVENTHANDLER_H_)
 #error Do not include eventhandler_macos.h directly; use eventhandler.h instead.
 #endif
@@ skipping 43 matching lines @@
   intptr_t fd() { return fd_; }
   Dart_Port port() { return port_; }
   intptr_t mask() { return mask_; }
   bool tracked_by_kqueue() { return tracked_by_kqueue_; }
   void set_tracked_by_kqueue(bool value) {
     tracked_by_kqueue_ = value;
   }
 
   // Returns true if the last token was taken.
   bool TakeToken() {
+    ASSERT(tokens_ > 0);
     tokens_--;
     return tokens_ == 0;
   }
 
   // Returns true if the tokens was 0 before adding.
   bool ReturnToken() {
     tokens_++;
     return tokens_ == 1;
   }
 
@@ skipping 34 matching lines @@
   TimeoutQueue timeout_queue_;
   bool shutdown_;
   int interrupt_fds_[2];
   int kqueue_fd_;
 };
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // BIN_EVENTHANDLER_MACOS_H_