Base: Truncate the timeout of WaitableEvent::TimedWait on Windows.

Base: Truncate the timeout of WaitableEvent::TimedWait on Windows.

The timeout has to be adjusted to milliseconds (the resolution of the
underlying call), but it should be truncated instead of extended,
because the documentation clearly states that the function can fail in
less time than the passed-in timeout, and by definition, the timeout
is the maximum time that the caller is willing to block.

BUG=none

Committed: https://crrev.com/d65edb7b2d228497056e18100c882f7cf7d59c36
Cr-Commit-Position: refs/heads/master@{#323178}

[rvargas (doing something else), 2015-03-30 23:44:45]

rvargas@chromium.org changed reviewers:
+ cpu@chromium.org

[cpu_(ooo_6.6-7.5), 2015-03-31 23:42:20]

lgtm

[rvargas (doing something else), 2015-04-01 03:05:49]

The CQ bit was checked by rvargas@chromium.org

[commit-bot: I haz the power, 2015-04-01 03:06:06]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1040833002/1

[commit-bot: I haz the power, 2015-04-01 04:03:03]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-04-01 04:03:56]

Patchset 1 (id:??) landed as
https://crrev.com/d65edb7b2d228497056e18100c882f7cf7d59c36
Cr-Commit-Position: refs/heads/master@{#323178}