Delays creating a snapshot file until after the snapshot is created.

R=iposva@google.com

Review URL: https://codereview.chromium.org//499743002

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart@39998 260f80e4-7a28-3924-810f-c04153c831b5
3 files changed