time: fallback to slower TestTicker test after one failure

TestTicker is sensitive to overloaded or slow systems, where a 20ms
ticker running for 10 ticks has a total run time out of the range
[110ms, 290ms]. To counter this flakiness, it tries five times to
get a successful result. This is insufficient--an overloaded test
machine can introduce more than 100ms of delay across the test.

Reduce the five attempts to two, but use a 1s ticker for 8 ticks
in the second attempt.

Updates #46474.
Updates #35692.

Change-Id: Ibd5187b00ccceeb981b652f2af9a1c3766357b78
Reviewed-on: https://go-review.googlesource.com/c/go/+/339892
Trust: Damien Neil <dneil@google.com>
Run-TryBot: Damien Neil <dneil@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

0 files changed, 0 insertions, 0 deletions