[dart:io] Move Platform.ansiSupported to {Stdin,Stdout}.supportsAnsiEscapes

sdk/lib/io/platform.dart

 // 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;
 
 /**
  * Information about the environment in which the current program is running.
  *
  * Platform provides information such as the operating system,
@@ skipping 53 matching lines @@
  * [Dart by Example](https://www.dartlang.org/dart-by-example/#dart-io-and-command-line-apps)
  * provides additional task-oriented code samples that show how to use
  * various API from the [dart:io] library.
  */
 class Platform {
   static final _numberOfProcessors = _Platform.numberOfProcessors;
   static final _pathSeparator = _Platform.pathSeparator;
   static final _operatingSystem = _Platform.operatingSystem;
   static final _localHostname = _Platform.localHostname;
   static final _version = _Platform.version;
-  static final _ansiSupported = _Platform.ansiSupported;
 
   /**
    * Get the number of processors of the machine.
    */
   static int get numberOfProcessors => _numberOfProcessors;
 
   /**
    * Get the path separator used by the operating system to separate
    * components in file paths.
    */
@@ skipping 34 matching lines @@
    * Returns true if the operating system is iOS.
    */
   static final bool isIOS = (_operatingSystem == "ios");
 
   /**
    * Returns true if the operating system is Fuchsia
    */
   static final bool isFuchsia = (_operatingSystem == "fuchsia");
 
   /**
-    * When stdio is connected to a terminal, whether ANSI codes are supported.
-    *
-    * This value is hard-coded to `true`, except on Windows where only more
-    * recent versions of Windows 10 support the codes.
-    */
-  static final bool ansiSupported = _ansiSupported;
-
-  /**
    * Get the environment for this process.
    *
    * The returned environment is an unmodifiable map which content is
    * retrieved from the operating system on its first use.
    *
    * Environment variables on Windows are case-insensitive. The map
    * returned on Windows is therefore case-insensitive and will convert
    * all keys to upper case. On other platforms the returned map is
    * a standard case-sensitive map.
    */
@@ skipping 68 matching lines @@
   /**
    * Returns the version of the current Dart runtime.
    *
    * The returned `String` is formatted as the
    * [semver](http://semver.org) version string of the current dart
    * runtime, possibly followed by whitespace and other version and
    * build details.
    */
   static String get version => _version;
 }