Remove references to AnalysisDriver from the plugin mixin classes

pkg/analyzer_plugin/test/plugin/fix_mixin_test.dart

 // Copyright (c) 2017, 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.
 
 import 'dart:async';
 
 import 'package:analyzer/error/error.dart';
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/file_system/memory_file_system.dart';
 import 'package:analyzer/src/dart/analysis/driver.dart';
@@ skipping 67 matching lines @@
 
 class _TestServerPlugin extends MockServerPlugin with FixesMixin {
   _TestServerPlugin(ResourceProvider resourceProvider)
       : super(resourceProvider);
 
   PrioritizedSourceChange createChange() {
     return new PrioritizedSourceChange(0, new SourceChange(''));
   }
 
   @override
-  List<FixContributor> getFixContributors(AnalysisDriverGeneric driver) {
+  List<FixContributor> getFixContributors(String path) {
     return <FixContributor>[
       new _TestFixContributor(<PrioritizedSourceChange>[createChange()]),
       new _TestFixContributor(
           <PrioritizedSourceChange>[createChange(), createChange()])
     ];
   }
 
   @override
-  Future<FixesRequest> getFixesRequest(EditGetFixesParams parameters,
-      covariant AnalysisDriverGeneric driver) async {
+  Future<FixesRequest> getFixesRequest(EditGetFixesParams parameters) async {
     int offset = parameters.offset;
     AnalysisError error = new AnalysisError(
         new MockSource(), 0, 0, CompileTimeErrorCode.AWAIT_IN_WRONG_CONTEXT);
     AnalysisResult result = new AnalysisResult(null, null, null, null, null,
         null, new LineInfo([0, 20]), null, null, [error], null);
     return new DartFixesRequestImpl(resourceProvider, offset, [error], result);
   }
 }