Add fields to platform library, implement them on runtime dart.

sdk/lib/platform/platform.dart

 // Copyright (c) 2013, 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.
 
 /**
  * Runtime information about the current platform.
  */
 library dart.platform;
+
+/**
+ * The number of processors of the platform.
+ *
+ * Returns null if no information is available.
+ *
+ * Supported on the standalone Dart executable.
+ */
+external int get numberOfProcessors;
+
+/**
+ * The path separator used on the platform to separate
+ * components in file paths.
+ */
+external String get pathSeparator;
+
+/**
+ * A string (`linux`, `macos`, `windows` or `android`)
+ * representing the operating system.
+ *
+ * Returns null if the operating system could not be determined.
+ */
+external String get operatingSystem;
+
+/**
+ * The local hostname for the system.
+ *
+ * Returns null if the local hostname is not available.
+ *
+ * Supported on the standalone Dart executable.
+ */
+external String get localHostname;
+
+/**
+ * The version of the current Dart runtime.
+ *
+ * Returns null if not running a Dart runtime.
+ *
+ * Supported on the standalone Dart executable.
+ */
+external String get version;
+
+/**

[Ivan Posva, 2013/10/25 17:03:48]

These specific testers are problematic. Let's assume that we or a third-party
ports Dart to BSD, now they would have to change the dart:platform API.

[Bill Hesse, 2013/10/25 17:50:00]

Removed in CL 43773004

+ * True if the operating system is Linux.
+ */
+// TODO(6997): Replace with bool get isLinux => operatingSystem == 'linux'
+// when issue with patched top-level functions is fixed.
+external bool get isLinux;
+
+/**
+ * True if the operating system is Mac OS.
+ */
+external bool get isMacOS;
+
+/**
+ * True if the operating system is Windows.
+ */
+external bool get isWindows;
+
+/**
+ * True if the operating system is Android.
+ */
+external bool get isAndroid;
+
+/**
+ * The environment for this instance of the platform.
+ *
+ * If environment variables are not supported on this platform, or not
+ * available, null is returned.
+ *
+ * Environment variables on Windows are case-insensitive. The map
+ * returned on Windows is therefore case-insensitive and converts
+ * all keys and key arguments to its methods to upper case.
+ * On other platforms the returned map is
+ * a standard case-sensitive map.
+ *
+ * Supported on the standalone Dart executable.
+ */
+external Map<String, String> get environment;
+
+/**
+ * The path of the executable this Dart isolate is running on.
+ *
+ * Returns null if the execution environment does not make the information
+ * available.
+ *
+ * Supported on the standalone Dart executable.
+ */
+external String get executable;
+
+/**
+ * The URI of the script being run in this isolate.
+ *
+ * If the URI is relative it is relative to the file URI of
+ * the working directory of the VM when it was started.
+ *
+ * Returns null if the executable environment does not make the information
+ * available.
+ *
+ * Supported on the standalone Dart executable.
+ */
+external Uri get script;
+
+/**
+ * The flags passed to the executable used to run the script in this
+ * isolate. These are the command-line flags between the executable name
+ * and the script name.
+ *
+ * Returns the empty list if [executableArguments] is not supported.
+ *
+ * Supported on the standalone Dart executable.
+ */
+external List<String> get executableArguments;
+
+/**
+ * The value of the --package-root flag passed to the executable
+ * used to run the script in this isolate.  This is the directory in which
+ * Dart packages are looked up.
+ *
+ * If there is no --package-root flag, then the empty string is returned.
+ *
+ * Returns null if the information is not available on this platform.
+ *
+ * Supported on the standalone Dart executable.
+ */
+external String get packageRoot;