Attempt to make stream-timeout test less flaky.
Attempt to make stream-timeout test less flaky.

If the periodic timer gets starved long enough, the timeout might
happen. If the 5ms periodic timer hasn't triggered in 250ms, discard
the test (i.e., don't fail anyway).

R=ajohnsen@google.com

Review URL: https://codereview.chromium.org//137143014

git-svn-id: c93d8a2297af3b929165606efe145742a534bc71@32054 260f80e4-7a28-3924-810f-c04153c831b5

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