- Apply review comments from https://codereview.chromium.org/232223004/

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 82 matching lines @@
   static String get operatingSystem => _operatingSystem;
 
   /**
    * Get the local hostname for the system.
    */
   static String get localHostname => _localHostname;
 
   /**
    * Returns true if the operating system is Linux.
    */
-  static bool get isLinux => _operatingSystem == "linux";
+  static final bool isLinux = (_operatingSystem == "linux");
 
   /**
    * Returns true if the operating system is Mac OS.
    */
-  static bool get isMacOS => _operatingSystem == "macos";
+  static final bool isMacOS = (_operatingSystem == "macos");
 
   /**
    * Returns true if the operating system is Windows.
    */
-  static bool get isWindows => _operatingSystem == "windows";
+  static final bool isWindows = (_operatingSystem == "windows");
 
   /**
    * Returns true if the operating system is Android.
    */
-  static bool get isAndroid => _operatingSystem == "android";
+  static final bool isAndroid = (_operatingSystem == "android");
 
   /**
    * 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
@@ skipping 43 matching lines @@
    *
    * If there is no --package-root flag, then the empty string is returned.
    */
   static String get packageRoot => _Platform.packageRoot;
 
   /**
    * Returns the version of the current Dart runtime.
    */
   static String get version => _version;
 }