Move mojo and mojom from mojo/public/dart to mojo/dart/packages

mojo/public/dart/mojom/lib/src/commands/gen.dart

-// Copyright 2015 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-library mojom.command.tree;
-
-import 'dart:async';
-import 'dart:io';
-
-import 'package:args/args.dart';
-import 'package:args/command_runner.dart';
-import 'package:mojom/src/commands/mojom_command.dart';
-import 'package:mojom/src/generate.dart';
-import 'package:mojom/src/utils.dart';
-import 'package:path/path.dart' as path;
-
-class GenCommand extends MojomCommand {
-  String get name => 'gen';
-  String get description =>
-      'Generate bindings for .mojom files under --mojom-root into Dart '
-      'packages under --output';
-  String get invocation => 'mojom.dart gen -r mojoms/ -o dart-packages/';
-
-  Directory _dartRoot;
-
-  GenCommand() {
-    argParser.addOption('output',
-        abbr: 'o',
-        defaultsTo: Directory.current.path,
-        help: 'Directory where Dart packages live into which we generate the '
-            'resulting bindings.');
-  }
-
-  run() async {
-    MojomCommand.setupLogging();
-    await _validateArguments();
-    var treeGenerator =
-        new TreeGenerator(mojoSdk, mojomRoot, _dartRoot, skips, dryRun: dryRun);
-    await treeGenerator.generate();
-    return treeGenerator.errors;
-  }
-
-  _validateArguments() async {
-    await validateArguments();
-    _dartRoot = new Directory(makeAbsolute(argResults['output']));
-    if (!await _dartRoot.exists()) {
-      throw new CommandLineError(
-          'Specified --output directory $_dartRoot does not exist');
-    }
-  }
-}