Extract DiagnosticReporter implementation from Compiler.

tests/compiler/dart2js/message_kind_helper.dart

 // Copyright (c) 2013, 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 dart2js.test.message_kind_helper;
 
 import 'package:expect/expect.dart';
 import 'dart:async';
 
 import 'package:compiler/src/commandline_options.dart';
@@ skipping 96 matching lines @@
       bool messageFound = false;
       List unexpectedMessages = [];
       for (String message in messages) {
         if (!messageFound && new RegExp('^$pattern\$').hasMatch(message)) {
           messageFound = true;
         } else {
           unexpectedMessages.add(message);
         }
       }
       Expect.isTrue(messageFound, '"$pattern" does not match any in $messages');
-      Expect.isFalse(compiler.hasCrashed);
+      Expect.isFalse(compiler.reporter.hasCrashed);
       if (!unexpectedMessages.isEmpty) {
         for (String message in unexpectedMessages) {
           print("Unexpected message: $message");
         }
         if (!kindsWithExtraMessages.contains(template.kind)) {
           // Try changing the error reporting logic before adding an exception
           // to [kindsWithExtraMessages].
           throw 'Unexpected messages found.';
         }
       }
 
       bool pendingStuff = false;
       for (var e in compiler.resolver.pendingClassesToBePostProcessed) {
         pendingStuff = true;
-        compiler.reportInfo(
+        compiler.reporter.reportInfo(
             e, MessageKind.GENERIC,
             {'text': 'Pending class to be post-processed.'});
       }
       for (var e in compiler.resolver.pendingClassesToBeResolved) {
         pendingStuff = true;
-        compiler.reportInfo(
+        compiler.reporter.reportInfo(
             e, MessageKind.GENERIC,
             {'text': 'Pending class to be resolved.'});
       }
       Expect.isTrue(!pendingStuff ||
                     kindsWithPendingClasses.contains(template));
 
       if (!pendingStuff) {
         // If there is pending stuff, or the compiler was cancelled, we
         // shouldn't reuse the compiler.
         cachedCompiler = compiler;
       }
     });
   }).then((_) => cachedCompiler);
 }