tools/testing: move code into individual libraries

tools/testing/dart/utils.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 utils;
 
 import 'dart:io';
-import 'dart:math' show min;
 import 'dart:convert';
 
-part 'legacy_path.dart';
+import 'path.dart';
 
 // This is the maximum time we expect stdout/stderr of subprocesses to deliver
 // data after we've got the exitCode.
 const Duration MAX_STDIO_DELAY = const Duration(seconds: 30);
 
 String MAX_STDIO_DELAY_PASSED_MESSAGE =
 """Not waiting for stdout/stderr from subprocess anymore 
 ($MAX_STDIO_DELAY passed). Please note that this could be an indicator 
 that there is a hanging process which we were unable to kill.""";
 
@@ skipping 280 matching lines @@
 
 class UniqueObject {
   static int _nextId = 1;
   final int _hashCode;
 
   int get hashCode => _hashCode;
   operator==(other) => other is UniqueObject && _hashCode == other._hashCode;
 
   UniqueObject() : _hashCode = ++_nextId;
 }