Migrate dart2js stubs for dart:io

tool/input_sdk/lib/io/platform_impl.dart

Index: tool/input_sdk/lib/io/platform_impl.dart
diff --git a/tool/input_sdk/lib/io/platform_impl.dart b/tool/input_sdk/lib/io/platform_impl.dart
new file mode 100644
index 0000000000000000000000000000000000000000..4ce43ea1e65507f09bbfac97a6919a66a90297ca
--- /dev/null
+++ b/tool/input_sdk/lib/io/platform_impl.dart
@@ -0,0 +1,121 @@
+// 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.
+
+part of dart.io;
+
+class _Platform {
+  external static int _numberOfProcessors();
+  external static String _pathSeparator();
+  external static String _operatingSystem();
+  external static _localHostname();
+  external static _executable();
+  external static _resolvedExecutable();
+  /**
+   * Retrieve the entries of the process environment.
+   *
+   * The result is an [Iterable] of strings, where each string represents
+   * an environment entry.
+   *
+   * Environment entries should be strings containing
+   * a non-empty name and a value separated by a '=' character.
+   * The name does not contain a '=' character,
+   * so the name is everything up to the first '=' character.
+   * Values are everything after the first '=' charcacter.
+   * A value may contain further '=' characters, and it may be empty.
+   *
+   * Returns an [OSError] if retrieving the environment fails.
+   */
+  external static _environment();
+  external static List<String> _executableArguments();
+  external static String _packageRoot();
+  external static String _packageConfig();
+  external static String _version();
+
+  static String executable = _executable();
+  static String resolvedExecutable = _resolvedExecutable();
+  static String packageRoot = _packageRoot();
+  static String packageConfig = _packageConfig();
+
+  // Cache the OS environemnt. This can be an OSError instance if
+  // retrieving the environment failed.
+  static var _environmentCache;
+
+  static int get numberOfProcessors => _numberOfProcessors();
+  static String get pathSeparator => _pathSeparator();
+  static String get operatingSystem => _operatingSystem();
+  static Uri script;
+
+  static String get localHostname {
+    var result = _localHostname();
+    if (result is OSError) {
+      throw result;
+    } else {
+      return result;
+    }
+  }
+
+  static List<String> get executableArguments => _executableArguments();
+
+  static Map<String, String> get environment {
+    if (_environmentCache == null) {
+      var env = _environment();
+      if (env is !OSError) {
+        var isWindows = operatingSystem == 'windows';
+        var result = isWindows ? new _CaseInsensitiveStringMap() : new Map();
+        for (var str in env) {
+          // The Strings returned by [_environment()] are expected to be
+          // valid environment entries, but exceptions have been seen
+          // (e.g., an entry of just '=' has been seen on OS/X).
+          // Invalid entries (lines without a '=' or with an empty name)
+          // are discarded.
+          var equalsIndex = str.indexOf('=');
+          if (equalsIndex > 0) {
+            result[str.substring(0, equalsIndex)] =
+                str.substring(equalsIndex + 1);
+          }
+        }
+        _environmentCache = new UnmodifiableMapView<String, String>(result);
+      } else {
+        _environmentCache = env;
+      }
+    }
+
+    if (_environmentCache is OSError) {
+      throw _environmentCache;
+    } else {
+      return _environmentCache;
+    }
+  }
+
+  static String get version => _version();
+}
+
+// Environment variables are case-insensitive on Windows. In order
+// to reflect that we use a case-insensitive string map on Windows.
+class _CaseInsensitiveStringMap<V> implements Map<String, V> {
+  final Map<String, V> _map = new Map<String, V>();
+
+  bool containsKey(Object key) =>
+      key is String && _map.containsKey(key.toUpperCase());
+  bool containsValue(Object value) => _map.containsValue(value);
+  V operator [](Object key) => key is String ? _map[key.toUpperCase()] : null;
+  void operator []=(String key, V value) {
+    _map[key.toUpperCase()] = value;
+  }
+  V putIfAbsent(String key, V ifAbsent()) {
+    return _map.putIfAbsent(key.toUpperCase(), ifAbsent);
+  }
+  void addAll(Map other) {
+    other.forEach((key, value) => this[key.toUpperCase()] = value);
+  }
+  V remove(Object key) => key is String ? _map.remove(key.toUpperCase()) : null;
+  void clear() { _map.clear(); }
+  void forEach(void f(String key, V value)) { _map.forEach(f); }
+  Iterable<String> get keys => _map.keys;
+  Iterable<V> get values => _map.values;
+  int get length => _map.length;
+  bool get isEmpty => _map.isEmpty;
+  bool get isNotEmpty => _map.isNotEmpty;
+  String toString() => _map.toString();
+}