Remove support for SDK dependencies.

utils/tests/pub/validator_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 validator_test;
 
 import 'dart:async';
 import 'dart:io';
 import 'dart:json' as json;
 import 'dart:math' as math;
@@ skipping 143 matching lines @@
     integration('has a non-Dart file in lib', () {
       dir(appPath, [
         libPubspec("test_pkg", "1.0.0"),
         dir("lib", [
           file("thing.txt", "woo hoo")
         ])
       ]).scheduleCreate();
       expectNoValidationError(lib);
     });
 
-    integration('has an unconstrained dependency on "unittest"', () {
-      dir(appPath, [
-        libPubspec("test_pkg", "1.0.0", deps: [
-          {'hosted': 'unittest'}
-        ])
-      ]).scheduleCreate();
-      expectNoValidationError(dependency);
-    });
-
     integration('has a nested directory named "tools"', () {
       dir(appPath, [
         dir("foo", [dir("tools")])
       ]).scheduleCreate();
       expectNoValidationError(directory);
     });
 
     integration('is <= 10 MB', () {
       expectNoValidationError(size(100));
       expectNoValidationError(size(10 * math.pow(2, 20)));
@@ skipping 393 matching lines @@
     });
 
     test('has a README with invalid utf-8', () {
       dir(appPath, [
         binaryFile("README", [192])
       ]).scheduleCreate();
       expectValidationWarning(utf8Readme);
     });
   });
 }