By default use current code page on Windows for decoding string

sdk/lib/io/process.dart

Index: sdk/lib/io/process.dart
diff --git a/sdk/lib/io/process.dart b/sdk/lib/io/process.dart
index f2062df562aa9f937731c494d2eef21edfa52253..87ff798df7688a26411b6ced4aa0aca83c1a7ca2 100644
--- a/sdk/lib/io/process.dart
+++ b/sdk/lib/io/process.dart
@@ -148,7 +148,7 @@ class ProcessOptions {
    * This option is ignored for interactive processes started with
    * [:Process.start:].
    *
-   * The default stdoutEncoding is UTF_8.
+   * The default stdoutEncoding is SYSTEM.

[Søren Gjesse, 2012/12/07 12:00:11]

Are we going to try to explain what that means?

[Mads Ager (google), 2012/12/07 12:50:02]

Yes. I used to have a comment in Encoding on the constant. I'll add that again.

    */
   Encoding stdoutEncoding;
 
@@ -159,7 +159,7 @@ class ProcessOptions {
    * This option is ignored for interactive processes started with
    * [:Process.start:].
    *
-   * The default stderrEncoding is UTF_8.
+   * The default stderrEncoding is SYSTEM.
    */
   Encoding stderrEncoding;