Fix safari browser to use Future.value

tools/testing/dart/android.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.
 
 library android;
 
 import "dart:io";
 import "dart:async";
 import "dart:core";
 import "dart:utf";
@@ skipping 17 matching lines @@
  * [_executeCommandRaw] will write [stdin] to the standard input of the created
  * process and will return a tuple (stdout, stderr).
  *
  * If the exit code of the process was nonzero it will complete with an error.
  * If starting the process failed, it will complete with an error as well.
  */
 Future _executeCommandRaw(String executable,
                           List<String> args,
                           [String stdin = ""]) {
   Future<String> getOutput(Stream<List<int>> stream) {
-    return stream.transform(new StringDecoder())
-        .reduce(new StringBuffer(), (buf, data) {
-          buf.write(data);
-          return buf;
-    }).then((buf) => buf.toString());
+    return stream.transform(new StringDecoder()).toList()
+        .then((data) => data.join(""));
   }
 
   DebugLogger.info("Running: '\$ $executable ${args.join(' ')}'");
   return Process.start(executable, args).then((Process process) {
     if (stdin != null && stdin != '') {
       process.stdin.write(stdin);
     }
     process.stdin.close();
 
     var futures = [getOutput(process.stdout),
@@ skipping 265 matching lines @@
  */
 class Intent {
   String action;
   String package;
   String activity;
   String dataUri;
 
   Intent(this.action, this.package, this.activity, [this.dataUri]);
 }