remove docgen source and targets from build

pkg/docgen/lib/src/mdn.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.
-
-library docgen.mdn;
-
-import 'dart:convert';
-import 'dart:io';
-
-import 'package:logging/logging.dart';
-import 'package:path/path.dart' as p;
-
-// TODO(janicejl): Make MDN content generic or pluggable.
-
-/// Map of all the comments for dom elements from MDN.
-Map<String, dynamic> _mdn;
-
-/// Generates MDN comments from database.json.
-String mdnComment(String root, Logger logger, String domName) {
-  //Check if MDN is loaded.
-  if (_mdn == null) {
-    // Reading in MDN related json file.
-    var mdnPath = p.join(root, 'utils/apidoc/mdn/database.json');
-    var mdnFile = new File(mdnPath);
-    if (mdnFile.existsSync()) {
-      _mdn = JSON.decode(mdnFile.readAsStringSync());
-    } else {
-      logger.warning("Cannot find MDN docs expected at $mdnPath");
-      _mdn = {};
-    }
-  }
-
-  var parts = domName.split('.');
-  if (parts.length == 2) return _mdnMemberComment(parts[0], parts[1]);
-  if (parts.length == 1) return _mdnTypeComment(parts[0]);
-
-  throw new StateError('More than two items is not supported: $parts');
-}
-
-/// Generates the MDN Comment for variables and method DOM elements.
-String _mdnMemberComment(String type, String member) {
-  var mdnType = _mdn[type];
-  if (mdnType == null) return '';
-  var mdnMember = mdnType['members'].firstWhere((e) => e['name'] == member,
-      orElse: () => null);
-  if (mdnMember == null) return '';
-  if (mdnMember['help'] == null || mdnMember['help'] == '') return '';
-  if (mdnMember['url'] == null) return '';
-  return _htmlifyMdn(mdnMember['help'], mdnMember['url']);
-}
-
-/// Generates the MDN Comment for class DOM elements.
-String _mdnTypeComment(String type) {
-  var mdnType = _mdn[type];
-  if (mdnType == null) return '';
-  if (mdnType['summary'] == null || mdnType['summary'] == "") return '';
-  if (mdnType['srcUrl'] == null) return '';
-  return _htmlifyMdn(mdnType['summary'], mdnType['srcUrl']);
-}
-
-/// Encloses the given content in an MDN div and the original source link.
-String _htmlifyMdn(String content, String url) {
-  return '<div class="mdn">' + content.trim() + '<p class="mdn-note">'
-      '<a href="' + url.trim() + '">from Mdn</a></p></div>';
-}