Extract EmbedderRelatedTest to a utility file

pkg/analyzer/test/src/context/builder_test.dart

 // Copyright (c) 2016, 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 analyzer.test.src.context.context_builder_test;
 
 import 'dart:io' as io;
 
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/file_system/memory_file_system.dart';
 import 'package:analyzer/file_system/physical_file_system.dart';
 import 'package:analyzer/source/package_map_resolver.dart';
 import 'package:analyzer/src/context/builder.dart';
 import 'package:analyzer/src/context/source.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/sdk.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:package_config/packages.dart';
 import 'package:package_config/src/packages_impl.dart';
 import 'package:path/path.dart' as path;
 import 'package:unittest/unittest.dart';
 
+import '../../embedder_tests.dart';
 import '../../generated/test_support.dart';
 import '../../reflective_tests.dart';
-import '../../source/embedder_test.dart';
 import '../../utils.dart';
 import 'mock_sdk.dart';
 
 main() {
   initializeTestEnvironment();
   runReflectiveTests(ContextBuilderTest_WithDisk);
   runReflectiveTests(ContextBuilderTest_WithoutDisk);
   runReflectiveTests(EmbedderYamlLocatorTest);
 }
 
@@ skipping 680 matching lines @@
     expect(locator.embedderYamls, hasLength(0));
   }
 
   void test_valid() {
     EmbedderYamlLocator locator = new EmbedderYamlLocator({
       'fox': [pathTranslator.getResource('/tmp')]
     });
     expect(locator.embedderYamls, hasLength(1));
   }
 }