Factor out reporting from rules

lib/src/codegen/code_generator.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 dev_compiler.src.codegen.code_generator;
 
 import 'dart:io';
 
 import 'package:analyzer/src/generated/ast.dart' show CompilationUnit;
 import 'package:analyzer/src/generated/element.dart'
     show CompilationUnitElement, LibraryElement;
 import 'package:path/path.dart' as path;
 
 import 'package:dev_compiler/src/info.dart';
 import 'package:dev_compiler/src/utils.dart' show canonicalLibraryName;
-import 'package:dev_compiler/src/report.dart';
 import 'package:dev_compiler/src/checker/rules.dart';
 
 abstract class CodeGenerator {
   final String outDir;
   final Uri root;
   final TypeRules rules;
 
   static List<String> _searchPaths = () {
     // TODO(vsm): Can we remove redundancy with multi_package_resolver logic?
     var packagePaths =
@@ skipping 98 matching lines @@
     return new Uri(
         scheme: 'package', path: path.joinAll(parts.sublist(index + 1)));
   }
 
   CodeGenerator(String outDir, this.root, this.rules)
       : outDir = path.absolute(outDir);
 
   /// Return a hash, if any, that can be used for caching purposes. When two
   /// invocations to this function return the same hash, the underlying
   /// code-generator generated the same code.
-  String generateLibrary(
-      LibraryUnit unit, LibraryInfo info, CheckerReporter reporter);
+  String generateLibrary(LibraryUnit unit, LibraryInfo info);
 }