Reland^2 "Add Chromium-style TimeDelta, Time and TimeTicks classes, and a new ElapsedTimer class."

Reland^2 "Add Chromium-style TimeDelta, Time and TimeTicks classes, and a new ElapsedTimer class."

These classes are meant to replace OS::Ticks() and OS::TimeCurrentMillis(),
which are broken in several ways. The ElapsedTimer class implements a
stopwatch using TimeTicks::HighResNow() for high resolution, monotonic
timing.

Also fix the CpuProfile::GetStartTime() and CpuProfile::GetEndTime()
methods to actually return the time relative to the unix epoch as stated
in the documentation (previously that was relative to some arbitrary
point in time, i.e. boot time).

The previous Windows issues have been resolved, and we now use GetTickCount64()
on Windows Vista and later, falling back to timeGetTime() with rollover
protection for earlier Windows versions.

BUG=v8:2853
R=machenbach@chromium.org, yurys@chromium.org

Committed: https://code.google.com/p/v8/source/detail?r=16413

[Benedikt Meurer, 2013-08-29 08:54:01]

PTAL

[Michael Achenbach, 2013-08-29 09:08:15]

On 2013/08/29 08:54:01, Benedikt Meurer wrote:
> PTAL

lgtm

[yurys, 2013-08-29 09:11:41]

LGTM,

we should probably update RolloverProtectedNow in base/time in Chromium to also
use GetTickCount64 when it is available.

[Benedikt Meurer, 2013-08-29 09:15:42]

Committed patchset #2 manually as r16413.

[Benedikt Meurer, 2013-08-29 09:18:20]

On 2013/08/29 09:11:41, Yury Semikhatsky wrote:
> we should probably update RolloverProtectedNow in base/time in Chromium to
also
> use GetTickCount64 when it is available.

Feel free to copy to Chromium, once we are sure that it's working in V8 now. :-)