Closes stdin after starting a new process for a test.
Closes stdin after starting a new process for a test.

It is a mistake if a test tries to block to wait for
input on stdin. If we close stdin in the test script
after the test process starts, reading from stdin
will indicate that a test can fail immediately
rather than timing out.
Review URL: https://codereview.chromium.org//12521020

git-svn-id: c93d8a2297af3b929165606efe145742a534bc71@20386 260f80e4-7a28-3924-810f-c04153c831b5

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