Add an extension point for contributing to HTML_ERRORS.

pkg/analyzer/test/src/task/html_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 test.src.task.html_test;
 
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer/src/task/html.dart';
 import 'package:analyzer/task/html.dart';
 import 'package:analyzer/task/model.dart';
@@ skipping 157 matching lines @@
 </body>
 </html>''');
     computeResult(target, REFERENCED_LIBRARIES, matcher: isDartScriptsTask);
     expect(outputs[REFERENCED_LIBRARIES], hasLength(1));
     expect(outputs[DART_SCRIPTS], hasLength(0));
   }
 }
 
 @reflectiveTest
 class HtmlErrorsTaskTest extends AbstractContextTest {
-  test_buildInputs() {
-    Source source = newSource('/test.html');
-    Map<String, TaskInput> inputs = HtmlErrorsTask.buildInputs(source);
-    expect(inputs, isNotNull);
-    expect(
-        inputs.keys,
-        unorderedEquals([
-          HtmlErrorsTask.DART_ERRORS_INPUT,
-          HtmlErrorsTask.DOCUMENT_ERRORS_INPUT
-        ]));
-  }
-
   test_constructor() {
     Source source = newSource('/test.html');
     HtmlErrorsTask task = new HtmlErrorsTask(context, source);
     expect(task, isNotNull);
     expect(task.context, context);
     expect(task.target, source);
   }
 
   test_createTask() {
     Source source = newSource('/test.html');
@@ skipping 118 matching lines @@
     <h1 Test>
   </body>
 </html>
 ''');
     computeResult(target, HTML_DOCUMENT);
     expect(task, isParseHtmlTask);
     expect(outputs[HTML_DOCUMENT], isNotNull);
     expect(outputs[HTML_DOCUMENT_ERRORS], isNotEmpty);
   }
 }