Fix checking path for windows
Fix checking path for windows

Change-Id: I7ad6bb40be07dc2cf9d609c7c379dc7ec6725da1
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/146400
Reviewed-by: Konstantin Shcheglov <09e4d7516628963212bf4aace2f97603d2b706e4@google.com>
Commit-Queue: Keerti Parthasarathy <50d1d8bfaf73a210aebf5aef847d5b7b93955336@google.com>

dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk,dart-lang/sdk