Transparent Retries not Cancelling properly

[kjlubick]

To reproduce:

1. Start a task
2. Task errors out with BOT_DIED
3. Swarming retries the task
4. New task is PENDING
5. Cancel Task

Observe that the summary task result (e.g. for task 33e91f3119745610) says cancelled. The task result for the first run properly says BOT_DIED (e.g. 33e91f3119745611).

There is no task result for run 2 (e.g. 33e91f3119745612), which is not correct.

Also observe that the try_number for the summary task result incorrectly says 1, not 2.