Revert "Revert "Use native async/await support in pub.""

sdk/lib/_internal/pub_generated/lib/src/ascii_tree.dart

Index: sdk/lib/_internal/pub_generated/lib/src/ascii_tree.dart
diff --git a/sdk/lib/_internal/pub_generated/lib/src/ascii_tree.dart b/sdk/lib/_internal/pub_generated/lib/src/ascii_tree.dart
deleted file mode 100644
index ca8d5103c2b0b1c1a04775c610eb69330bd3d978..0000000000000000000000000000000000000000
--- a/sdk/lib/_internal/pub_generated/lib/src/ascii_tree.dart
+++ /dev/null
@@ -1,173 +0,0 @@
-// 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.
-
-/// A simple library for rendering tree-like structures in ASCII.
-library pub.ascii_tree;
-
-import 'package:path/path.dart' as path;
-
-import 'log.dart' as log;
-import 'utils.dart';
-
-/// Draws a tree for the given list of files. Given files like:
-///
-///     TODO
-///     example/console_example.dart
-///     example/main.dart
-///     example/web copy/web_example.dart
-///     test/absolute_test.dart
-///     test/basename_test.dart
-///     test/dirname_test.dart
-///     test/extension_test.dart
-///     test/is_absolute_test.dart
-///     test/is_relative_test.dart
-///     test/join_test.dart
-///     test/normalize_test.dart
-///     test/relative_test.dart
-///     test/split_test.dart
-///     .gitignore
-///     README.md
-///     lib/path.dart
-///     pubspec.yaml
-///     test/all_test.dart
-///     test/path_posix_test.dart
-///     test/path_windows_test.dart
-///
-/// this renders:
-///
-///     |-- .gitignore
-///     |-- README.md
-///     |-- TODO
-///     |-- example
-///     |   |-- console_example.dart
-///     |   |-- main.dart
-///     |   '-- web copy
-///     |       '-- web_example.dart
-///     |-- lib
-///     |   '-- path.dart
-///     |-- pubspec.yaml
-///     '-- test
-///         |-- absolute_test.dart
-///         |-- all_test.dart
-///         |-- basename_test.dart
-///         | (7 more...)
-///         |-- path_windows_test.dart
-///         |-- relative_test.dart
-///         '-- split_test.dart
-///
-/// If [baseDir] is passed, it will be used as the root of the tree.
-///
-/// If [showAllChildren] is `false`, then directories with more than ten items
-/// will have their contents truncated. Defaults to `false`.
-String fromFiles(List<String> files, {String baseDir, bool showAllChildren}) {
-  // Parse out the files into a tree of nested maps.
-  var root = {};
-  for (var file in files) {
-    if (baseDir != null) file = path.relative(file, from: baseDir);
-    var parts = path.split(file);
-    var directory = root;
-    for (var part in path.split(file)) {
-      directory = directory.putIfAbsent(part, () => {});
-    }
-  }
-
-  // Walk the map recursively and render to a string.
-  return fromMap(root, showAllChildren: showAllChildren);
-}
-
-/// Draws a tree from a nested map. Given a map like:
-///
-///     {
-///       "analyzer": {
-///         "args": {
-///           "collection": ""
-///         },
-///         "logging": {}
-///       },
-///       "barback": {}
-///     }
-///
-/// this renders:
-///
-///     analyzer
-///     |-- args
-///     |   '-- collection
-///     '---logging
-///     barback
-///
-/// Items with no children should have an empty map as the value.
-///
-/// If [showAllChildren] is `false`, then directories with more than ten items
-/// will have their contents truncated. Defaults to `false`.
-String fromMap(Map map, {bool showAllChildren}) {
-  var buffer = new StringBuffer();
-  _draw(buffer, "", null, map, showAllChildren: showAllChildren);
-  return buffer.toString();
-}
-
-void _drawLine(StringBuffer buffer, String prefix, bool isLastChild,
-    String name) {
-  // Print lines.
-  buffer.write(prefix);
-  if (name != null) {
-    if (isLastChild) {
-      buffer.write(log.gray("'-- "));
-    } else {
-      buffer.write(log.gray("|-- "));
-    }
-  }
-
-  // Print name.
-  buffer.writeln(name);
-}
-
-String _getPrefix(bool isRoot, bool isLast) {
-  if (isRoot) return "";
-  if (isLast) return "    ";
-  return log.gray("|   ");
-}
-
-void _draw(StringBuffer buffer, String prefix, String name, Map children,
-    {bool showAllChildren, bool isLast: false}) {
-  if (showAllChildren == null) showAllChildren = false;
-
-  // Don't draw a line for the root node.
-  if (name != null) _drawLine(buffer, prefix, isLast, name);
-
-  // Recurse to the children.
-  var childNames = ordered(children.keys);
-
-  drawChild(bool isLastChild, String child) {
-    var childPrefix = _getPrefix(name == null, isLast);
-    _draw(
-        buffer,
-        '$prefix$childPrefix',
-        child,
-        children[child],
-        showAllChildren: showAllChildren,
-        isLast: isLastChild);
-  }
-
-  if (name == null || showAllChildren || childNames.length <= 10) {
-    // Not too many, so show all the children.
-    for (var i = 0; i < childNames.length; i++) {
-      drawChild(i == childNames.length - 1, childNames[i]);
-    }
-  } else {
-    // Show the first few.
-    drawChild(false, childNames[0]);
-    drawChild(false, childNames[1]);
-    drawChild(false, childNames[2]);
-
-    // Elide the middle ones.
-    buffer.write(prefix);
-    buffer.write(_getPrefix(name == null, isLast));
-    buffer.writeln(log.gray('| (${childNames.length - 6} more...)'));
-
-    // Show the last few.
-    drawChild(false, childNames[childNames.length - 3]);
-    drawChild(false, childNames[childNames.length - 2]);
-    drawChild(true, childNames[childNames.length - 1]);
-  }
-}