Convert SessionLengthLimiter to OneShotTimer

Convert SessionLengthLimiter to OneShotTimer

This CL converts the SessionLengthLimiter from a RepeatingTimer that
fires once per second to a OneShotTimer that fires when the session
time is up and the user should be logged out.

BUG=175797
TEST=Manual, unittests


Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=182214

[bartfab (slow), 2013-02-12 20:13:54]

Hi Nikita,

Could you please review?

[Daniel Erat, 2013-02-12 20:40:43]

lgtm

https://chromiumcodereview.appspot.com/12218123/diff/1/chrome/browser/chromeo...
File chrome/browser/chromeos/power/session_length_limiter.cc (right):

https://chromiumcodereview.appspot.com/12218123/diff/1/chrome/browser/chromeo...
chrome/browser/chromeos/power/session_length_limiter.cc:119: timer_.reset();
what's the reason to destroy the timer here?

[bartfab (slow), 2013-02-13 10:32:59]

https://chromiumcodereview.appspot.com/12218123/diff/1/chrome/browser/chromeo...
File chrome/browser/chromeos/power/session_length_limiter.cc (right):

https://chromiumcodereview.appspot.com/12218123/diff/1/chrome/browser/chromeo...
chrome/browser/chromeos/power/session_length_limiter.cc:119: timer_.reset();
On 2013/02/12 20:40:43, Daniel Erat wrote:
> what's the reason to destroy the timer here?

This simply frees up the memory that the timer was occupying. The whole
indirection via a scoped_ptr exists as reviewers felt strongly that no timer
object should be occupying memory if the policy is disabled.

If the policy is disabled to begin with, no timer gets created. If the policy is
enabled and then later disabled, it seems only prudent to clean up and destry
the timer.

[commit-bot: I haz the power, 2013-02-13 10:34:41]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/bartfab@chromium.org/12218123/1

[commit-bot: I haz the power, 2013-02-13 14:27:30]

Change committed as 182214