Move MockSdk into tests.

test/mock_sdk.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.
 
 library linter.src.sdk;
 
 import 'package:analyzer/file_system/file_system.dart' as resource;
 import 'package:analyzer/file_system/memory_file_system.dart' as resource;
 import 'package:analyzer/src/context/cache.dart'
     show AnalysisCache, CachePartition;
@@ skipping 328 matching lines @@
   final String shortName;
   @override
   final String path;
   final String content;
   final List<_MockSdkFile> parts;
 
   const _MockSdkLibrary(this.shortName, this.path, this.content,
       [this.parts = const <_MockSdkFile>[]]);
 
   @override
-  String get category => throw unimplemented;
-
-  @override
-  bool get isDart2JsLibrary => throw unimplemented;
-
-  @override
-  bool get isDocumented => throw unimplemented;
-
-  @override
-  bool get isImplementation => throw unimplemented;
-
-  @override
-  bool get isInternal => throw unimplemented;
-
-  @override
-  bool get isShared => throw unimplemented;
-
-  @override
-  bool get isVmLibrary => throw unimplemented;
-
-  UnimplementedError get unimplemented => new UnimplementedError();
+  noSuchMethod(Invocation invocation) => super.noSuchMethod(invocation);
 }
 
 /// An [AnalysisContextImpl] that only contains sources for a Dart SDK.
 class _SdkAnalysisContext extends AnalysisContextImpl {
   final DartSdk sdk;
 
   _SdkAnalysisContext(this.sdk);
 
   @override
   AnalysisCache createCacheFromSourceFactory(SourceFactory factory) {
     if (factory == null) {
       return super.createCacheFromSourceFactory(factory);
     }
     return new AnalysisCache(
         <CachePartition>[AnalysisEngine.instance.partitionManager.forSdk(sdk)]);
   }
 }