tools/testing: move code into individual libraries

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:async";
 import "dart:convert" show LineSplitter, UTF8;
 import "dart:core";
 import "dart:io";
 
+import "path.dart";
 import "utils.dart";
 
 Future _executeCommand(String executable,
                        List<String> args,
                        [String stdin = ""]) {
   return _executeCommandRaw(executable, args, stdin).then((results) => null);
 }
 
 Future _executeCommandGetOutput(String executable,
                                 List<String> args,
@@ skipping 302 matching lines @@
  */
 class Intent {
   String action;
   String package;
   String activity;
   String dataUri;
 
   Intent(this.action, this.package, this.activity, [this.dataUri]);
 }