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

runtime/bin/stdio_patch.dart

Index: runtime/bin/stdio_patch.dart
diff --git a/runtime/bin/stdio_patch.dart b/runtime/bin/stdio_patch.dart
index e537dc87212029c4cb756032c4949d545cdb1897..3efd7d02675ab9efee6982954a3bc69a92858795 100644
--- a/runtime/bin/stdio_patch.dart
+++ b/runtime/bin/stdio_patch.dart
@@ -83,11 +83,20 @@
     }
   }
 
+  @patch bool get ansiSupported {
+    var result = _ansiSupported();
+    if (result is OSError) {
+      throw new StdinException("Error determining ANSI support", result);
+    }
+    return result;
+  }
+
   static _echoMode() native "Stdin_GetEchoMode";
   static _setEchoMode(bool enabled) native "Stdin_SetEchoMode";
   static _lineMode() native "Stdin_GetLineMode";
   static _setLineMode(bool enabled) native "Stdin_SetLineMode";
   static _readByte() native "Stdin_ReadByte";
+  static _ansiSupported() native "Stdin_AnsiSupported";
 }
 
 @patch class Stdout {
@@ -112,6 +121,16 @@
   }
 
   static _getTerminalSize(int fd) native "Stdout_GetTerminalSize";
+
+  @patch static bool _ansiSupported(int fd) {
+    var result = _getAnsiSupported(fd);
+    if (result is! bool) {
+      throw new StdoutException("Error determining ANSI support", result);
+    }
+    return result;
+  }
+
+  static _getAnsiSupported(int fd) native "Stdout_AnsiSupported";
 }