Switch pkg packages, pub, and dartdoc to use package: imports.

pkg/scheduled_test/test/metatest.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.
 
 /// A test library for testing test libraries? We must go deeper.
 ///
 /// Since unit testing code tends to use a lot of global state, it can be tough
 /// to test. This library manages it by running each test case in a child
 /// isolate, then reporting the results back to the parent isolate.
 library metatest;
 
 import 'dart:io';
 import 'dart:async';
 import 'dart:isolate';
 
-import '../../../pkg/pathos/lib/path.dart' as path;
-import '../../../pkg/unittest/lib/unittest.dart';
+import 'package:pathos/path.dart' as path;
+import 'package:unittest/unittest.dart';
 
 import 'utils.dart';
 
 // TODO(nweiz): get rid of this once issue 8863 is fixed.
 /// The path to the Dart executable. This is only set in a child isolate.
 String get dartExecutable => _executable;
 String _executable;
 
 /// Declares a test with the given [description] and [body]. [body] corresponds
 /// to the `main` method of a test file, and will be run in an isolate. By
@@ skipping 180 matching lines @@
         "message": testCase.message,
         "result": testCase.result,
         "stackTrace": testCase.stackTrace
       }).toList()
     });
   }
 
   void onInit() {}
   void onDone(bool success) {}
 }