Delete the old html_json docs stuff.

tools/html_json_doc/bin/html_json_doc.dart

-// Copyright (c) 2012, 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.
-
-/**
- * TODO(amouravski): Document stuff here.
- */
-
-import 'dart:io';
-
-import '../lib/html_to_json.dart' as html_to_json;
-import '../lib/json_to_html.dart' as json_to_html;
-import '../../../pkg/args/lib/args.dart';
-
-// Need this because ArgParser.getUsage doesn't show command invocation.
-const USAGE = 'Usage htmlJsonDoc [options] --mode=<mode> <HTML.dart directory> '
-    '<json path>\n[options] include:';
-final argParser = new ArgParser();
-
-main() {
-  final args = new Options().arguments;
-
-  if (args.isEmpty) {
-    printUsage('No arguments provided.');
-    return;
-  }
-
-  var mode;
-  argParser.addOption('mode', abbr: 'm',
-      help: '(Required) Convert from HTML docs to JSON or vice versa.',
-      allowed: ['html-to-json', 'json-to-html'], allowedHelp: {
-        'html-to-json': 'Processes all HTML .dart files at given\n'
-          'location and outputs JSON.',
-          'json-to-html': 'Takes JSON file at location and inserts docs into\n'
-      'HTML .dart files.'},
-      callback: (m) => mode = m
-  );
-
-  final argResults = argParser.parse(args);
-
-  if (mode == null) {
-    printUsage('Mode is a required option.');
-    return;
-  } else if (argResults.rest.length < 2) {
-    printUsage('Insufficient arguments.');
-    return;
-  }
-
-  var htmlPath = new Path(argResults.rest[0]);
-  var jsonPath = new Path(argResults.rest[1]);
-
-  var convertFuture;
-  if (mode == 'html-to-json') {
-    convertFuture = html_to_json.convert(htmlPath, jsonPath);
-  } else {
-    convertFuture = json_to_html.convert(htmlPath, jsonPath);
-  }
-
-  convertFuture.then((anyErrors) {
-    print('Completed ${anyErrors ? "with" : "without"} errors.');
-  });
-}
-
-/// Prints the usage of the tool. [message] is printed if provided.
-void printUsage([String message]) {
-  print(message);
-  print(USAGE);
-  print(argParser.getUsage());
-}