Add interfaces for a new compiler API.

pkg/dart2js_incremental/lib/caching_compiler.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.
 
 part of dart2js_incremental;
 
 /// Do not call this method directly. It will be made private.
 // TODO(ahe): Make this method private.
 Future<Compiler> reuseCompiler(
-    {DiagnosticHandler diagnosticHandler,
-     CompilerInputProvider inputProvider,
-     CompilerOutputProvider outputProvider,
+    {CompilerDiagnostics diagnosticHandler,
+     CompilerInput inputProvider,
+     CompilerOutput outputProvider,
      List<String> options: const [],
      Compiler cachedCompiler,
      Uri libraryRoot,
      Uri packageRoot,
      bool packagesAreImmutable: false,
      Map<String, dynamic> environment,
      Future<bool> reuseLibrary(LibraryElement library)}) {
   UserTag oldTag = new UserTag('_reuseCompiler').makeCurrent();
   if (libraryRoot == null) {
     throw 'Missing libraryRoot';
@@ skipping 166 matching lines @@
   final Map<String, String> output = new Map<String, String>();
 
   EventSink<String> call(String name, String extension) {
     return new StringEventSink((String data) {
       output['$name.$extension'] = data;
     });
   }
 
   String operator[] (String key) => output[key];
 }