Remove many things that depend on frog.

samples/pond/compiler.dart

-// Copyright (c) 2011, 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.
-
-/** Embeds the frog compiler as a worker isolate. */
-#library('compiler');
-
-#import('dart:isolate', prefix: 'isolate');
-#import("../../frog/file_system_dom.dart");
-#import("../../frog/lang.dart", prefix: 'frog');
-
-main() {
-  final fileSystem = new DomFileSystem();
-  isolate.port.receive((input, replyTo) {
-    final watch = new Stopwatch.start();
-    // Each message is a compilation request.
-    fileSystem.writeString("user.dart", input['code']);
-    frog.parseOptions('../../frog', ['dummyArg1', 'dummyArg2', 'user.dart'],
-      fileSystem);
-    frog.options.useColors = false;
-    frog.options.warningsAsErrors = input['warningsAsErrors'];
-    frog.initializeWorld(fileSystem);
-
-    // Collect compilation messages
-    final warnings = [];
-    frog.world.messageHandler = (prefix, msg, span) {
-      final warning = { 'prefix': prefix, 'msg': msg};
-
-      if (span != null) {
-        warning['filename'] = span.file.filename;
-        warning['line'] = span.line;
-        warning['column'] = span.column;
-        warning['endLine'] = span.endLine;
-        warning['endColumn'] = span.endColumn;
-        warning['locationText'] = span.locationText;
-      }
-      warnings.add(warning);
-    };
-
-    bool success = frog.world.compile();
-    watch.stop();
-
-    // Send results back to the requester isolate.
-    String output = success ? frog.world.getGeneratedCode() : null;
-    replyTo.send({
-      'success': success,
-      'code': output,
-      'warnings': warnings,
-      'time': watch.elapsedInMs()});
-  });
-}