Regenerate pub sources.

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

Index: sdk/lib/_internal/pub_generated/lib/src/system_cache.dart
diff --git a/sdk/lib/_internal/pub_generated/lib/src/system_cache.dart b/sdk/lib/_internal/pub_generated/lib/src/system_cache.dart
index d558ad0036a1df0f07a42599dd3315f448e4a3e1..650861522274b37a151e5b3a53a404d73f272ede 100644
--- a/sdk/lib/_internal/pub_generated/lib/src/system_cache.dart
+++ b/sdk/lib/_internal/pub_generated/lib/src/system_cache.dart
@@ -1,6 +1,13 @@
+// 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.
+
 library pub.system_cache;
+
 import 'dart:async';
+
 import 'package:path/path.dart' as path;
+
 import 'io.dart';
 import 'io.dart' as io show createTempDir;
 import 'log.dart' as log;
@@ -11,38 +18,76 @@ import 'source/hosted.dart';
 import 'source/path.dart';
 import 'source.dart';
 import 'source_registry.dart';
+
+/// The system-wide cache of downloaded packages.
+///
+/// This cache contains all packages that are downloaded from the internet.
+/// Packages that are available locally (e.g. path dependencies) don't use this
+/// cache.
 class SystemCache {
+  /// The root directory where this package cache is located.
   final String rootDir;
+
   String get tempDir => path.join(rootDir, '_temp');
+
+  /// The sources from which to get packages.
   final sources = new SourceRegistry();
+
+  /// Creates a new package cache which is backed by the given directory on the
+  /// user's file system.
   SystemCache(this.rootDir);
+
+  /// Creates a system cache and registers the standard set of sources.
+  ///
+  /// If [isOffline] is `true`, then the offline hosted source will be used.
+  /// Defaults to `false`.
   factory SystemCache.withSources(String rootDir, {bool isOffline: false}) {
     var cache = new SystemCache(rootDir);
     cache.register(new GitSource());
+
     if (isOffline) {
       cache.register(new OfflineHostedSource());
     } else {
       cache.register(new HostedSource());
     }
+
     cache.register(new PathSource());
     cache.sources.setDefault('hosted');
     return cache;
   }
+
+  /// Registers a new source.
+  ///
+  /// This source must not have the same name as a source that's already been
+  /// registered.
   void register(Source source) {
     source.bind(this);
     sources.register(source);
   }
+
+  /// Determines if the system cache contains the package identified by [id].
   Future<bool> contains(PackageId id) {
     var source = sources[id.source];
+
     if (source is! CachedSource) {
       throw new ArgumentError("Package $id is not cacheable.");
     }
+
     return source.isInSystemCache(id);
   }
+
+  /// Create a new temporary directory within the system cache.
+  ///
+  /// The system cache maintains its own temporary directory that it uses to
+  /// stage packages into while downloading. It uses this instead of the OS's
+  /// system temp directory to ensure that it's on the same volume as the pub
+  /// system cache so that it can move the directory from it.
   String createTempDir() {
     var temp = ensureDir(tempDir);
     return io.createTempDir(temp, 'dir');
   }
+
+  /// Deletes the system cache's internal temp directory.
   void deleteTempDir() {
     log.fine('Clean up system cache temp directory $tempDir.');
     if (dirExists(tempDir)) deleteEntry(tempDir);