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

sdk/lib/_internal/pub_generated/lib/src/command/cache_add.dart

Index: sdk/lib/_internal/pub_generated/lib/src/command/cache_add.dart
diff --git a/sdk/lib/_internal/pub_generated/lib/src/command/cache_add.dart b/sdk/lib/_internal/pub_generated/lib/src/command/cache_add.dart
deleted file mode 100644
index 1ad264662d0df13683913247bc68a2a8f86e5730..0000000000000000000000000000000000000000
--- a/sdk/lib/_internal/pub_generated/lib/src/command/cache_add.dart
+++ /dev/null
@@ -1,96 +0,0 @@
-// 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 pub.command.cache_add;
-
-import 'dart:async';
-
-import 'package:pub_semver/pub_semver.dart';
-
-import '../command.dart';
-import '../log.dart' as log;
-import '../package.dart';
-import '../utils.dart';
-
-/// Handles the `cache add` pub command.
-class CacheAddCommand extends PubCommand {
-  String get name => "add";
-  String get description => "Install a package.";
-  String get invocation =>
-      "pub cache add <package> [--version <constraint>] [--all]";
-  String get docUrl => "http://dartlang.org/tools/pub/cmd/pub-cache.html";
-
-  CacheAddCommand() {
-    argParser.addFlag(
-        "all",
-        help: "Install all matching versions.",
-        negatable: false);
-
-    argParser.addOption("version", abbr: "v", help: "Version constraint.");
-  }
-
-  Future run() {
-    // Make sure there is a package.
-    if (argResults.rest.isEmpty) {
-      usageException("No package to add given.");
-    }
-
-    // Don't allow extra arguments.
-    if (argResults.rest.length > 1) {
-      var unexpected = argResults.rest.skip(1).map((arg) => '"$arg"');
-      var arguments = pluralize("argument", unexpected.length);
-      usageException("Unexpected $arguments ${toSentence(unexpected)}.");
-    }
-
-    var package = argResults.rest.single;
-
-    // Parse the version constraint, if there is one.
-    var constraint = VersionConstraint.any;
-    if (argResults["version"] != null) {
-      try {
-        constraint = new VersionConstraint.parse(argResults["version"]);
-      } on FormatException catch (error) {
-        usageException(error.message);
-      }
-    }
-
-    // TODO(rnystrom): Support installing from git too.
-    var source = cache.sources["hosted"];
-
-    // TODO(rnystrom): Allow specifying the server.
-    return source.getVersions(package, package).then((versions) {
-      versions = versions.where(constraint.allows).toList();
-
-      if (versions.isEmpty) {
-        // TODO(rnystrom): Show most recent unmatching version?
-        fail("Package $package has no versions that match $constraint.");
-      }
-
-      downloadVersion(Version version) {
-        var id = new PackageId(package, source.name, version, package);
-        return cache.contains(id).then((contained) {
-          if (contained) {
-            // TODO(rnystrom): Include source and description if not hosted.
-            // See solve_report.dart for code to harvest.
-            log.message("Already cached ${id.name} ${id.version}.");
-            return null;
-          }
-
-          // Download it.
-          return source.downloadToSystemCache(id);
-        });
-      }
-
-      if (argResults["all"]) {
-        // Install them in ascending order.
-        versions.sort();
-        return Future.forEach(versions, downloadVersion);
-      } else {
-        // Pick the best matching version.
-        versions.sort(Version.prioritize);
-        return downloadVersion(versions.last);
-      }
-    });
-  }
-}