Restructure pkg/unittest and pkg/webdriver to follow the pub conventions.

tests/html/shadowroot_test.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.
 
-#library('ShadowRootTest');
-#import('../../pkg/unittest/unittest.dart');
-#import('../../pkg/unittest/html_config.dart');
-#import('dart:html');
+library ShadowRootTest;
+import '../../pkg/unittest/lib/unittest.dart';
+import '../../pkg/unittest/lib/html_config.dart';
+import 'dart:html';
 
 main() {
   useHtmlConfiguration();
 
   var isShadowRoot =
       predicate((x) => x is ShadowRoot, 'is a ShadowRoot');
 
   test('ShadowRoot supported', () {
     var isSupported = ShadowRoot.supported;
 
     // If it's supported, then it should work. Otherwise should fail.
     if (isSupported) {
       var shadowRoot = new ShadowRoot(new DivElement());
       expect(shadowRoot, isShadowRoot);
     } else {
       expect(() => new ShadowRoot(new DivElement()), throws);
     }
   });
 }