Fixes leak in Process.runSync().
Fixes leak in Process.runSync().

This removes the call to _stdin._sink.destroy()
from my previous CL, which broke a test.
stdin is closed by the native implementation.
Closing again shouldn't cause a problem, but
it looks like destroy() attempts to do a lot
more than that.

OTOH adding the remove call is sufficient to
fix the leak, so let's just stick with that.

R=iposva@google.com

Review URL: https://codereview.chromium.org//687163004

git-svn-id: c93d8a2297af3b929165606efe145742a534bc71@41395 260f80e4-7a28-3924-810f-c04153c831b5

dart-lang/sdk,dart-lang/sdk,dartino/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dart-lang/sdk,dartino/dart-sdk,dart-archive/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dart-archive/dart-sdk,dartino/dart-sdk,dart-lang/sdk,dart-archive/dart-sdk,dart-lang/sdk,dartino/dart-sdk,dartino/dart-sdk