Add "environment" parameter to spawnUri for String.fromEnvironment support.

sdk/lib/isolate/isolate.dart

 // 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.
 
 /**
  * Concurrent programming using _isolates_:
  * independent workers that are similar to threads
  * but don't share memory,
  * communicating only via messages.
  */
@@ skipping 219 matching lines @@
    * This resolution also applies to the main entry [uri]
    * if that happens to be a package-URI.
    *
    * If both [packageRoot] and [packages] are omitted, the new isolate uses
    * the same package resolution as the current isolate.
    * It's not allowed to provide both a `packageRoot` and a `package` parameter.
    *
    * WARNING: The [packageRoot] and [packages] parameters are not implemented
    * on all platforms yet.
    *
+   * The [environment] is a mapping from strings to strings which the
+   * spawned isolate uses when looking up [String.fromEnvironment] values.
+   * The system may add its own entries to environment as well.
+   * If `environment` is omitted, the spawned isolate has the same environment
+   * declarations as the spawning isolate.
+   *
+   * WARNING: The [environment] parameter is not implemented on all
+   * platforms yet.
+   *
    * Returns a future that will complete with an [Isolate] instance if the
    * spawning succeeded. It will complete with an error otherwise.
    */
   external static Future<Isolate> spawnUri(
       Uri uri,
       List<String> args,
       var message,
       {bool paused: false,
+       SendPort onExit,
+       SendPort onError,
+       bool errorsAreFatal,
        bool checked,
+       Map<String, String> environment,
        Uri packageRoot,
-       Map<String, Uri> packages,
-       bool errorsAreFatal,
-       SendPort onExit,
-       SendPort onError});
+       Map<String, Uri> packages});
 
   /**
    * Requests the isolate to pause.
    *
    * The isolate should stop handling events by pausing its event queue.
    * The request will eventually make the isolate stop doing anything.
    * It will be handled before any other messages that are later sent to the
    * isolate from the current isolate, but no other guarantees are provided.
    *
    * The event loop may be paused before previously sent, but not yet exeuted,
@@ skipping 383 matching lines @@
  * as the original error, but has no other features of the original error.
  */
 class RemoteError implements Error {
   final String _description;
   final StackTrace stackTrace;
   RemoteError(String description, String stackDescription)
       : _description = description,
         stackTrace = new StackTrace.fromString(stackDescription);
   String toString() => _description;
 }