Improve type information and minor clean up

pkg/analyzer/test/src/task/options_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.
 
 library analyzer.test.src.task.options_test;
 
 import 'package:analyzer/analyzer.dart';
 import 'package:analyzer/source/analysis_options_provider.dart';
 import 'package:analyzer/source/error_processor.dart';
 import 'package:analyzer/src/generated/engine.dart';
@@ skipping 87 matching lines @@
 
   test_configure_error_processors() {
     configureContext('''
 analyzer:
   errors:
     invalid_assignment: ignore
     unused_local_variable: error
 ''');
 
     List<ErrorProcessor> processors =
-        context.getConfigurationData(CONFIGURED_ERROR_PROCESSORS)
-        as List<ErrorProcessor>;
+        context.getConfigurationData(CONFIGURED_ERROR_PROCESSORS);
     expect(processors, hasLength(2));
 
     var unused_local = new AnalysisError(
         new TestSource(), 0, 1, HintCode.UNUSED_LOCAL_VARIABLE, [
       ['x']
     ]);
     var invalid_assignment =
         new AnalysisError(new TestSource(), 0, 1, HintCode.INVALID_ASSIGNMENT, [
       ['x'],
       ['y']
@@ skipping 279 matching lines @@
         [AnalysisOptionsWarningCode.UNSUPPORTED_OPTION_WITH_LEGAL_VALUE]);
   }
 
   void validate(String source, List<ErrorCode> expected) {
     var options = optionsProvider.getOptionsFromString(source);
     var errors = validator.validate(options);
     expect(errors.map((AnalysisError e) => e.errorCode),
         unorderedEquals(expected));
   }
 }