lib/convert: removed unused import, removed redundant test

tests/lib/convert/json_lib_test.dart

 // Copyright (c) 2011, 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 json_tests;
 import 'package:unittest/unittest.dart';
 import 'dart:convert';
 
 main() {
   test('Parse', () {
@@ skipping 63 matching lines @@
     expect(JSON.encode(5), equals('5'));
     expect(JSON.encode(-42), equals('-42'));
     // Dart does not guarantee a formatting for doubles,
     // so reparse and compare to the original.
     validateRoundTrip(3.14);
     expect(JSON.encode(true), equals('true'));
     expect(JSON.encode(false), equals('false'));
     expect(JSON.encode(null), equals('null'));
     expect(JSON.encode(' hi there" bob '), equals('" hi there\\" bob "'));
     expect(JSON.encode('hi\\there'), equals('"hi\\\\there"'));
-    // TODO(devoncarew): these tests break the dartium build

[ricow1, 2014/04/03 05:29:22]

Devon: is there a bug for this that we can close off

[devoncarew, 2014/04/03 07:24:28]

Sorry, no. This comment dates back to when I started on the Dart project - I've
lost a bit of context :)

I _think_ this comment was here because my CL at the time also included a fix to
the stringify implementation. At the time, the bots would run the tests against
the current version of Dartium, and not the one that was building w/ the changed
encoding.

-    //expect(JSON.encode('hi\nthere'), equals('"hi\\nthere"'));
-    //expect(JSON.encode('hi\r\nthere'), equals('"hi\\r\\nthere"'));
+    expect(JSON.encode('hi\nthere'), equals('"hi\\nthere"'));
+    expect(JSON.encode('hi\r\nthere'), equals('"hi\\r\\nthere"'));
     expect(JSON.encode(''), equals('""'));
 
     // Lists.
     expect(JSON.encode([]), equals('[]'));
     expect(JSON.encode(new List(0)), equals('[]'));
     expect(JSON.encode(new List(3)), equals('[null,null,null]'));
     validateRoundTrip([3, -4.5, null, true, 'hi', false]);
     expect(JSON.encode([[3], [], [null], ['hi', true]]),
       equals('[[3],[],[null],["hi",true]]'));
 
@@ skipping 83 matching lines @@
 var throwsJsonError =
     throwsA(new isInstanceOf<JsonUnsupportedObjectError>());
 
 /**
  * Checks that the argument can be converted to a JSON string and
  * back, and produce something equivalent to the argument.
  */
 validateRoundTrip(expected) {
   expect(JSON.decode(JSON.encode(expected)), equals(expected));
 }