Add test for time resolution of User Timing

Add test for time resolution of User Timing

Resolution of performance.now() is reduced in r198348 to prevent
timing attacks. Since User Timing uses PerformanceBase::now()
internally, its resolution should be now 5 microseconds.

BUG=506723
Committed: https://src.chromium.org/viewvc/blink?view=rev&revision=198381

[Kunihiko Sakamoto, 2015-07-07 04:58:38]

Patchset #1 (id:1) has been deleted

[Kunihiko Sakamoto, 2015-07-07 05:33:05]

ksakamoto@chromium.org changed reviewers:
+ inferno@chromium.org

[inferno, 2015-07-07 06:03:46]

lgtm

https://codereview.chromium.org/1216643007/diff/20001/LayoutTests/http/tests/...
File LayoutTests/http/tests/misc/webtiming-resolution.html (right):

https://codereview.chromium.org/1216643007/diff/20001/LayoutTests/http/tests/...
LayoutTests/http/tests/misc/webtiming-resolution.html:16: console.log(t1);
I don't think you want this line ?

https://codereview.chromium.org/1216643007/diff/20001/LayoutTests/http/tests/...
LayoutTests/http/tests/misc/webtiming-resolution.html:32:
testTimeResolution(function() { return performance.now() });
nit: define function() { return performance.now() as function
timeByPerformanceNow() and then use it here.

[Kunihiko Sakamoto, 2015-07-07 06:08:14]

https://codereview.chromium.org/1216643007/diff/20001/LayoutTests/http/tests/...
File LayoutTests/http/tests/misc/webtiming-resolution.html (right):

https://codereview.chromium.org/1216643007/diff/20001/LayoutTests/http/tests/...
LayoutTests/http/tests/misc/webtiming-resolution.html:16: console.log(t1);
On 2015/07/07 06:03:46, inferno wrote:
> I don't think you want this line ?

Oops, removed.

https://codereview.chromium.org/1216643007/diff/20001/LayoutTests/http/tests/...
LayoutTests/http/tests/misc/webtiming-resolution.html:32:
testTimeResolution(function() { return performance.now() });
On 2015/07/07 06:03:46, inferno wrote:
> nit: define function() { return performance.now() as function
> timeByPerformanceNow() and then use it here.

Done.

[Kunihiko Sakamoto, 2015-07-07 06:08:55]

The CQ bit was checked by ksakamoto@chromium.org

[Kunihiko Sakamoto, 2015-07-07 06:08:55]

The patchset sent to the CQ was uploaded after l-g-t-m from inferno@chromium.org
Link to the patchset: https://codereview.chromium.org/1216643007/#ps40001
(title: " ")

[commit-bot: I haz the power, 2015-07-07 06:09:03]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1216643007/40001

[commit-bot: I haz the power, 2015-07-07 06:30:53]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-07-07 06:30:54]

Try jobs failed on following builders:
  linux_blink_rel on tryserver.blink (JOB_FAILED,
http://build.chromium.org/p/tryserver.blink/builders/linux_blink_rel/builds/6...)

[Kunihiko Sakamoto, 2015-07-07 09:08:28]

The CQ bit was checked by ksakamoto@chromium.org

[commit-bot: I haz the power, 2015-07-07 09:08:47]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1216643007/40001

[commit-bot: I haz the power, 2015-07-07 09:12:15]

Committed patchset #2 (id:40001) as
https://src.chromium.org/viewvc/blink?view=rev&revision=198381