Add Process.runSync for running processe synchronously.

sdk/lib/io/process.dart

 // Copyright (c) 2013, 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.
 
 part of dart.io;
 
 // TODO(ager): The only reason for this class is that we
 // cannot patch a top-level at this point.
 class _ProcessUtils {
   external static void _exit(int status);
@@ skipping 129 matching lines @@
   external static Future<ProcessResult> run(
       String executable,
       List<String> arguments,
       {String workingDirectory,
        Map<String, String> environment,
        bool includeParentEnvironment: true,
        bool runInShell: false,
        Encoding stdoutEncoding: Encoding.SYSTEM,
        Encoding stderrEncoding: Encoding.SYSTEM});
 
+
+  /**
+   * Starts a process and runs it to completion. This is a synchronous
+   * call and will block until the child process terminates.
+   *
+   * The arguments are the same as for `Process.run`.
+   *
+   * Returns a `ProcessResult` with the result of running the process,
+   * i.e., exit code, standard out and standard in.
+   */
+  external static ProcessResult runSync(
+      String executable,
+      List<String> arguments,
+      {String workingDirectory,
+       Map<String, String> environment,
+       bool includeParentEnvironment: true,
+       bool runInShell: false,
+       Encoding stdoutEncoding: Encoding.SYSTEM,
+       Encoding stderrEncoding: Encoding.SYSTEM});
+
   /**
    * Returns the standard output stream of the process as a [:Stream:].
    *
    * Throws an [UnsupportedError] if the process is
    * non-interactive.
    */
   Stream<List<int>> get stdout;
 
   /**
    * Returns the standard error stream of the process as a [:Stream:].
@@ skipping 138 matching lines @@
   /**
    * Contains the system message for the process exception if any.
    */
   final String message;
 
   /**
    * Contains the OS error code for the process exception if any.
    */
   final int errorCode;
 }