Pluggable lint verifiers first step and basic lint task tests.

pkg/analyzer/lib/src/generated/engine.dart

 // Copyright (c) 2014, 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.
 
 // This code was auto-generated, is not intended to be edited, and is subject to
 // significant change. Please see the README file for more information.
 
 library engine;
 
 import "dart:math" as math;
@@ skipping 8818 matching lines @@
         "generate Dart lints for ${librarySource.fullName}";
   }
 
   @override
   accept(AnalysisTaskVisitor visitor) =>
       visitor.visitGenerateDartLintsTask(this);
 
   @override
   void internalPerform() {
 
-    List<CompilationUnit> compilationUnits =
+    Iterable<CompilationUnit> compilationUnits =
         _units.map((TimestampedData<CompilationUnit> unit) => unit.data);
     RecordingErrorListener errorListener = new RecordingErrorListener();
     LintGenerator lintGenerator =
         new LintGenerator(compilationUnits, errorListener);
     lintGenerator.generate();
 
     lintMap = new HashMap<Source, List<AnalysisError>>();
     compilationUnits.forEach((CompilationUnit unit) {
       Source source = unit.element.source;
       lintMap[source] = errorListener.getErrorsForSource(source);
@@ skipping 3312 matching lines @@
     if (element.id == _id) {
       result = element;
       throw new _ElementByIdFinderException();
     }
     super.visitElement(element);
   }
 }
 
 class _ElementByIdFinderException {
 }