Give Process.kill an optional argument to specify which signal to send.

runtime/bin/process_win.cc

 // 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.
 
 #include <process.h>
 
 #include "bin/builtin.h"
 #include "bin/process.h"
 #include "bin/eventhandler.h"
 #include "bin/thread.h"
@@ skipping 482 matching lines @@
   *exit_handler = reinterpret_cast<intptr_t>(exit_handle);
 
   CloseHandle(process_info.hThread);
 
   // Return process id.
   *id = process_info.dwProcessId;
   return 0;
 }
 
 
-bool Process::Kill(intptr_t id) {
+bool Process::Kill(intptr_t id, int signal) {
+  USE(signal);  // signal is not used on windows.
   HANDLE process_handle;
   HANDLE wait_handle;
   HANDLE exit_pipe;
   bool success = ProcessInfoList::LookupProcess(id,
                                                 &process_handle,
                                                 &wait_handle,
                                                 &exit_pipe);
   ASSERT(success);
   BOOL result = TerminateProcess(process_handle, -1);
   if (!result) {
     return false;
   }
   return true;
 }
 
 
 void Process::TerminateExitCodeHandler() {
   // Nothing needs to be done on Windows.
 }