[Regression] Re-enable ANSI color support on Windows (#9232)

Also adds a test to make sure we don't break it again.

dev/devicelab/pubspec.yaml

@@ -11,7 +11,7 @@ dependencies:
   args: ^0.13.4
   meta: ^1.0.4
   path: ^1.4.0
-  process: 2.0.1
+  process: 2.0.3
   stack_trace: ^1.4.0
   vm_service_client: '0.2.2+4'
 

packages/flutter_tools/lib/src/base/logger.dart

@@ -248,15 +248,6 @@ enum _LogType {
 }
 
 class AnsiTerminal {
-  AnsiTerminal() {
-    if (platform.isWindows) {
-      supportsColor = platform.ansiSupported;
-    } else {
-      final String term = platform.environment['TERM'];
-      supportsColor = (term != null && term != 'dumb');
-    }
-  }
-
   static const String _bold  = '\u001B[1m';
   static const String _reset = '\u001B[0m';
   static const String _clear = '\u001B[2J\u001B[H';
@@ -275,7 +266,7 @@ class AnsiTerminal {
     _INVALID_HANDLE,
   ];
 
-  bool supportsColor;
+  bool supportsColor = platform.stdoutSupportsAnsi;
 
   String bolden(String message) {
     if (!supportsColor)

packages/flutter_tools/pubspec.yaml

@@ -22,8 +22,8 @@ dependencies:
   meta: ^1.0.4
   mustache: ^0.2.5
   package_config: '>=0.1.5 <2.0.0'
-  platform: 1.1.1
-  process: 2.0.1
+  platform: 2.0.0
+  process: 2.0.3
   quiver: ^0.24.0
   stack_trace: ^1.4.0
   usage: ^3.0.1

packages/flutter_tools/test/src/base/logger_test.dart

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:flutter_tools/src/base/logger.dart';
+import 'package:flutter_tools/src/base/os.dart';
+import 'package:flutter_tools/src/base/version.dart';
+import 'package:test/test.dart';
+
+void main() {
+  group('AnsiLogger', () {
+    test('should support color on Windows version >= 10.0.10586', () {
+      final String name = new OperatingSystemUtils().name;
+      final String versionString = new RegExp(r'\d+\.\d+\.\d+').firstMatch(name).group(0);
+      final Version version = new Version.parse(versionString);
+      final bool shouldSupportColor = version >= new Version.parse('10.0.10586');
+
+      expect(new AnsiTerminal().supportsColor, shouldSupportColor);
+    }, testOn: 'windows');
+  });
+}