[dart:io] Adds a finalizer to _NativeSocket to avoid socket leaks

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 RUNTIME_BIN_PROCESS_H_
 #define RUNTIME_BIN_PROCESS_H_
 
 #include <errno.h>
 
 #include "bin/builtin.h"
@@ skipping 55 matching lines @@
   kSigtstp = 20,
   kSigttin = 21,
   kSigttou = 22,
   kSigurg = 23,
   kSigxcpu = 24,
   kSigxfsz = 25,
   kSigvtalrm = 26,
   kSigprof = 27,
   kSigwinch = 28,
   kSigpoll = 29,
-  kSigsys = 31
+  kSigsys = 31,
+  kLastSignal = kSigsys,
 };
 
 
 // To be kept in sync with ProcessStartMode consts in sdk/lib/io/process.dart.
 enum ProcessStartMode {
   kNormal = 0,
   kDetached = 1,
   kDetachedWithStdio = 2,
 };
 
@@ skipping 45 matching lines @@
   static void RunExitHook(int64_t exit_code) {
     if (exit_hook_ != NULL) {
       exit_hook_(exit_code);
     }
   }
 
   static intptr_t CurrentProcessId();
 
   static intptr_t SetSignalHandler(intptr_t signal);
   static void ClearSignalHandler(intptr_t signal);
+  static void ClearAllSignalHandlers();
 
   static Dart_Handle GetProcessIdNativeField(Dart_Handle process,
                                              intptr_t* pid);
   static Dart_Handle SetProcessIdNativeField(Dart_Handle process, intptr_t pid);
 
  private:
   static int global_exit_code_;
   static Mutex* global_exit_code_mutex_;
   static ExitHook exit_hook_;
 
@@ skipping 207 matching lines @@
 
  private:
   DISALLOW_COPY_AND_ASSIGN(BufferList);
 };
 #endif  // defined(HOST_OS_ANDROID) ...
 
 }  // namespace bin
 }  // namespace dart
 
 #endif  // RUNTIME_BIN_PROCESS_H_