Add support for binary stdout/stderr data when using Process.run

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 182 matching lines @@
  * [ProcessResult] represents the result of running a non-interactive
  * process started with [:Process.run:].
  */
 abstract class ProcessResult {
   /**
    * Exit code for the process.
    */
   int get exitCode;
 
   /**
-   * Standard output from the process as a string.
+   * Standard output from the process. The value used for the
+   * `stdoutEncoding` argument to `Process.run` determins the type. If
+   * `Encoding.BINARY` was used this value is of type `List<int>
+   * otherwise it is of type `String`.
    */
-  String get stdout;
+  get stdout;
 
   /**
-   * Standard error from the process as a string.
+   * Standard error from the process. The value used for the
+   * `stderrEncoding` argument to `Process.run` determins the type. If
+   * `Encoding.BINARY` was used this value is of type `List<int>
+   * otherwise it is of type `String`.
    */
-  String get stderr;
+  get stderr;
 
   /**
    * Process id from the process.
    */
   int get pid;
 }
 
 
 /**
  * On Posix systems, [ProcessSignal] is used to send a specific signal
@@ skipping 58 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;
 }