Fixes how to lookup sdk dir to support tests deeper inside test/ folders.
Fixes how to lookup sdk dir to support tests deeper inside test/ folders.

R=blois@google.com

Review URL: https://codereview.chromium.org//203723006

git-svn-id: f2efd3a053852389c2b5650f8031bc5c7fd052d9@34091 260f80e4-7a28-3924-810f-c04153c831b5

dart-archive/smoke,dart-lang/smoke