Use the new Base64 support from dart:convert in Observatory.

runtime/observatory/tests/service/get_object_rpc_test.dart

 // Copyright (c) 2015, 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.
 // VMOptions=--error_on_bad_type --error_on_bad_override
 
 library get_object_rpc_test;
 
 import 'dart:typed_data';
+import 'dart:convert' show BASE64;
 import 'package:observatory/service_io.dart';
-import 'package:observatory/base64.dart';
 import 'package:unittest/unittest.dart';
-
 import 'test_helper.dart';
 
 class _DummyClass {
   static var dummyVar = 11;
   void dummyFunction() {
   }
 }
 
 class _DummySubClass extends _DummyClass {
 }
@@ skipping 326 matching lines @@
     expect(result['id'], startsWith('objects/'));
     expect(result['valueAsString'], isNull);
     expect(result['class']['type'], equals('@Class'));
     expect(result['class']['name'], equals('_Uint8Array'));
     expect(result['size'], isPositive);
     expect(result['fields'], isEmpty);
     expect(result['length'], equals(3));
     expect(result['offset'], isNull);
     expect(result['count'], isNull);
     expect(result['bytes'], equals('AwIB'));
-    var bytes = decodeBase64(result['bytes']);
+    var bytes = BASE64.decode(result['bytes']);
     expect(bytes.buffer.asUint8List().toString(), equals('[3, 2, 1]'));
   },
 
   // Uint8List prefix.
   (Isolate isolate) async {
     // Call eval to get a Dart list.
     var evalResult = await eval(isolate, 'uint8List');
     var params = {
       'objectId': evalResult['id'],
       'count' : 2,
     };
     var result = await isolate.invokeRpcNoUpgrade('getObject', params);
     expect(result['type'], equals('Instance'));
     expect(result['kind'], equals('Uint8List'));
     expect(result['_vmType'], equals('TypedData'));
     expect(result['id'], startsWith('objects/'));
     expect(result['valueAsString'], isNull);
     expect(result['class']['type'], equals('@Class'));
     expect(result['class']['name'], equals('_Uint8Array'));
     expect(result['size'], isPositive);
     expect(result['fields'], isEmpty);
     expect(result['length'], equals(3));
     expect(result['offset'], isNull);
     expect(result['count'], equals(2));
     expect(result['bytes'], equals('AwI='));
-    var bytes = decodeBase64(result['bytes']);
+    var bytes = BASE64.decode(result['bytes']);
     expect(bytes.buffer.asUint8List().toString(), equals('[3, 2]'));
   },
 
   // Uint8List suffix.
   (Isolate isolate) async {
     // Call eval to get a Dart list.
     var evalResult = await eval(isolate, 'uint8List');
     var params = {
       'objectId': evalResult['id'],
       'offset' : 2,
       'count' : 2,
     };
     var result = await isolate.invokeRpcNoUpgrade('getObject', params);
     expect(result['type'], equals('Instance'));
     expect(result['kind'], equals('Uint8List'));
     expect(result['_vmType'], equals('TypedData'));
     expect(result['id'], startsWith('objects/'));
     expect(result['valueAsString'], isNull);
     expect(result['class']['type'], equals('@Class'));
     expect(result['class']['name'], equals('_Uint8Array'));
     expect(result['size'], isPositive);
     expect(result['fields'], isEmpty);
     expect(result['length'], equals(3));
     expect(result['offset'], equals(2));
     expect(result['count'], equals(1));
     expect(result['bytes'], equals('AQ=='));
-    var bytes = decodeBase64(result['bytes']);
+    var bytes = BASE64.decode(result['bytes']);
     expect(bytes.buffer.asUint8List().toString(), equals('[1]'));
   },
 
   // Uint8List with wacky offset.
   (Isolate isolate) async {
     // Call eval to get a Dart list.
     var evalResult = await eval(isolate, 'uint8List');
     var params = {
       'objectId': evalResult['id'],
       'offset' : 100,
@@ skipping 29 matching lines @@
     expect(result['id'], startsWith('objects/'));
     expect(result['valueAsString'], isNull);
     expect(result['class']['type'], equals('@Class'));
     expect(result['class']['name'], equals('_Uint64Array'));
     expect(result['size'], isPositive);
     expect(result['fields'], isEmpty);
     expect(result['length'], equals(3));
     expect(result['offset'], isNull);
     expect(result['count'], isNull);
     expect(result['bytes'], equals('AwAAAAAAAAACAAAAAAAAAAEAAAAAAAAA'));
-    var bytes = decodeBase64(result['bytes']);
+    var bytes = BASE64.decode(result['bytes']);
     expect(bytes.buffer.asUint64List().toString(), equals('[3, 2, 1]'));
   },
 
   // Uint64List prefix.
   (Isolate isolate) async {
     // Call eval to get a Dart list.
     var evalResult = await eval(isolate, 'uint64List');
     var params = {
       'objectId': evalResult['id'],
       'count' : 2,
     };
     var result = await isolate.invokeRpcNoUpgrade('getObject', params);
     expect(result['type'], equals('Instance'));
     expect(result['kind'], equals('Uint64List'));
     expect(result['_vmType'], equals('TypedData'));
     expect(result['id'], startsWith('objects/'));
     expect(result['valueAsString'], isNull);
     expect(result['class']['type'], equals('@Class'));
     expect(result['class']['name'], equals('_Uint64Array'));
     expect(result['size'], isPositive);
     expect(result['fields'], isEmpty);
     expect(result['length'], equals(3));
     expect(result['offset'], isNull);
     expect(result['count'], equals(2));
     expect(result['bytes'], equals('AwAAAAAAAAACAAAAAAAAAA=='));
-    var bytes = decodeBase64(result['bytes']);
+    var bytes = BASE64.decode(result['bytes']);
     expect(bytes.buffer.asUint64List().toString(), equals('[3, 2]'));
   },
 
   // Uint64List suffix.
   (Isolate isolate) async {
     // Call eval to get a Dart list.
     var evalResult = await eval(isolate, 'uint64List');
     var params = {
       'objectId': evalResult['id'],
       'offset' : 2,
       'count' : 2,
     };
     var result = await isolate.invokeRpcNoUpgrade('getObject', params);
     expect(result['type'], equals('Instance'));
     expect(result['kind'], equals('Uint64List'));
     expect(result['_vmType'], equals('TypedData'));
     expect(result['id'], startsWith('objects/'));
     expect(result['valueAsString'], isNull);
     expect(result['class']['type'], equals('@Class'));
     expect(result['class']['name'], equals('_Uint64Array'));
     expect(result['size'], isPositive);
     expect(result['fields'], isEmpty);
     expect(result['length'], equals(3));
     expect(result['offset'], equals(2));
     expect(result['count'], equals(1));
     expect(result['bytes'], equals('AQAAAAAAAAA='));
-    var bytes = decodeBase64(result['bytes']);
+    var bytes = BASE64.decode(result['bytes']);
     expect(bytes.buffer.asUint64List().toString(), equals('[1]'));
   },
 
   // Uint64List with wacky offset.
   (Isolate isolate) async {
     // Call eval to get a Dart list.
     var evalResult = await eval(isolate, 'uint64List');
     var params = {
       'objectId': evalResult['id'],
       'offset' : 100,
@@ skipping 329 matching lines @@
       caughtException = true;
       expect(e.code, equals(ServerRpcException.kInvalidParams));
       expect(e.message,
              "getObject: invalid 'objectId' parameter: code/0");
     }
     expect(caughtException, isTrue);
   },
 ];
 
 main(args) async => runIsolateTests(args, tests, testeeBefore:warmup);