Add interfaces for a new compiler API.

tests/compiler/dart2js/incremental/hello_test.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.
 
 // Test a sequence of modifications to hello-world which used to cause problems
 // on Try Dart.
 
 import 'dart:io' show
     Platform;
 
 import 'dart:async' show
     Future;
 
 import 'package:dart2js_incremental/dart2js_incremental.dart' show
     IncrementalCompiler;
 
 import 'package:compiler/compiler.dart' show
     Diagnostic;
 
-import 'package:compiler/src/dart2jslib.dart' show
-    NullSink;
+import 'package:compiler/src/null_compiler_output.dart' show
+    NullCompilerOutput;
+
+import 'package:compiler/src/old_to_new_api.dart' show
+    LegacyCompilerDiagnostics;
 
 import 'package:async_helper/async_helper.dart' show
     asyncTest;
 
 import 'package:expect/expect.dart' show
     Expect;
 
 import '../memory_source_file_helper.dart' show
     MemorySourceFileProvider;
 
@@ skipping 55 matching lines @@
   MemorySourceFileProvider provider =
       new MemorySourceFileProvider(tests);
   asyncTest(() => runTests(libraryRoot, packageRoot, provider));
 }
 
 Future runTests(
     Uri libraryRoot,
     Uri packageRoot,
     MemorySourceFileProvider provider) {
   IncrementalCompiler compiler = new IncrementalCompiler(
-      diagnosticHandler: handler,
+      diagnosticHandler: new LegacyCompilerDiagnostics(handler),
       inputProvider: provider,
-      outputProvider: NullSink.outputProvider,
+      outputProvider: const NullCompilerOutput(),
       options: ['--analyze-main'],
       libraryRoot: libraryRoot,
       packageRoot: packageRoot);
 
   return Future.forEach(tests.keys, (String testName) {
     Uri testUri = Uri.parse('memory:$testName');
     return compiler.compile(testUri).then((bool success) {
       Expect.equals(
           testResults[testName], success,
           'Compilation unexpectedly ${success ? "succeed" : "failed"}.');
     });
   });
 }
 
 void handler(Uri uri,
              int begin,
              int end,
              String message,
              Diagnostic kind) {
   if (kind != Diagnostic.VERBOSE_INFO) {
     print('$uri:$begin:$end:$message:$kind');
   }
 }