Reland of Fix computation of runtime for throttled tasks

Reland of Fix computation of runtime for throttled tasks (patchset #2 id:240001 of https://codereview.chromium.org/1741053002/ )

Reason for revert:
I reverted the wrong CL. Should have reverted the cherry-picked CL. So, re-reverting this one.

Original issue's description:
> Revert of Fix computation of runtime for throttled tasks (patchset #3 id:40001 of https://codereview.chromium.org/1718233002/ )
>
> Reason for revert:
> Speculative revert for Compile failure on Win, Mac & Precise 64 Beta Bots (crbug.com/590286)
>
> Original issue's description:
> > Fix computation of runtime for throttled tasks
> >
> > The computation of the delayed task runtime was computing the (virtual)
> > TimeDomain's now + delay.  That doesn't take into account the skew
> > between the real time and the virtual time, which meant timers could
> > run sooner than expected for background tabs.  Timers associated with
> > foreground tabs are unaffected.
> >
> > This patch makes the computation of delayed runtime  the responsibility
> > of the TimeDomain and introduces a ThrottledTimeDomain which computes
> > the delayed runtime as realtime + delay.
> >
> > This means timers will no longer run sooner than expected.  Under normal
> > circumstancs this only timers whose delay modulo 1000ms is less than 100
> > ms are less likely to be affected.  Timers whose whose delay modulo
> > 1000ms is greater than 900 are highly likely to be affected (there's a
> > good chance their delay was too small before).
> >
> > BUG=587074
> >
> > Committed: https://crrev.com/b56bbe4ce3e7276a130a00d83cf00e5672cd6be1
> > Cr-Commit-Position: refs/heads/master@{#376993}
>
> TBR=skyostil@chromium.org,alexclarke@chromium.org
> # Not skipping CQ checks because original CL landed more than 1 days ago.
> BUG=587074
>
> Committed: https://crrev.com/7a1d629da81d8218afbf86eb4ff6c977970cd8d4
> Cr-Commit-Position: refs/heads/master@{#377995}

TBR=skyostil@chromium.org,alexclarke@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=587074
Committed: https://crrev.com/cbfca553a3472a95aea36848988ac0dc3167e684
Cr-Commit-Position: refs/heads/master@{#378026}

[jaydasika, 2016-02-26 23:34:41]

Created Reland of Fix computation of runtime for throttled tasks

[commit-bot: I haz the power, 2016-02-26 23:41:04]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1727273008/1
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1727273008/1

[commit-bot: I haz the power, 2016-02-26 23:50:17]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-02-26 23:52:21]

Description was changed from

==========
Reland of Fix computation of runtime for throttled tasks (patchset #2 id:240001
of https://codereview.chromium.org/1741053002/ )

Reason for revert:
I reverted the wrong CL. Should have reverted the cherry-picked CL. So,
re-reverting this one.

Original issue's description:
> Revert of Fix computation of runtime for throttled tasks (patchset #3 id:40001
of https://codereview.chromium.org/1718233002/ )
> 
> Reason for revert:
> Speculative revert for Compile failure on Win, Mac & Precise 64 Beta Bots
(crbug.com/590286)
> 
> Original issue's description:
> > Fix computation of runtime for throttled tasks
> >
> > The computation of the delayed task runtime was computing the (virtual)
> > TimeDomain's now + delay.  That doesn't take into account the skew
> > between the real time and the virtual time, which meant timers could
> > run sooner than expected for background tabs.  Timers associated with
> > foreground tabs are unaffected.
> >
> > This patch makes the computation of delayed runtime  the responsibility
> > of the TimeDomain and introduces a ThrottledTimeDomain which computes
> > the delayed runtime as realtime + delay.
> >
> > This means timers will no longer run sooner than expected.  Under normal
> > circumstancs this only timers whose delay modulo 1000ms is less than 100
> > ms are less likely to be affected.  Timers whose whose delay modulo
> > 1000ms is greater than 900 are highly likely to be affected (there's a
> > good chance their delay was too small before).
> >
> > BUG=587074
> >
> > Committed: https://crrev.com/b56bbe4ce3e7276a130a00d83cf00e5672cd6be1
> > Cr-Commit-Position: refs/heads/master@{#376993}
> 
> TBR=skyostil@chromium.org,alexclarke@chromium.org
> # Not skipping CQ checks because original CL landed more than 1 days ago.
> BUG=587074
> 
> Committed: https://crrev.com/7a1d629da81d8218afbf86eb4ff6c977970cd8d4
> Cr-Commit-Position: refs/heads/master@{#377995}

TBR=skyostil@chromium.org,alexclarke@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=587074
==========

to

==========
Reland of Fix computation of runtime for throttled tasks (patchset #2 id:240001
of https://codereview.chromium.org/1741053002/ )

Reason for revert:
I reverted the wrong CL. Should have reverted the cherry-picked CL. So,
re-reverting this one.

Original issue's description:
> Revert of Fix computation of runtime for throttled tasks (patchset #3 id:40001
of https://codereview.chromium.org/1718233002/ )
>
> Reason for revert:
> Speculative revert for Compile failure on Win, Mac & Precise 64 Beta Bots
(crbug.com/590286)
>
> Original issue's description:
> > Fix computation of runtime for throttled tasks
> >
> > The computation of the delayed task runtime was computing the (virtual)
> > TimeDomain's now + delay.  That doesn't take into account the skew
> > between the real time and the virtual time, which meant timers could
> > run sooner than expected for background tabs.  Timers associated with
> > foreground tabs are unaffected.
> >
> > This patch makes the computation of delayed runtime  the responsibility
> > of the TimeDomain and introduces a ThrottledTimeDomain which computes
> > the delayed runtime as realtime + delay.
> >
> > This means timers will no longer run sooner than expected.  Under normal
> > circumstancs this only timers whose delay modulo 1000ms is less than 100
> > ms are less likely to be affected.  Timers whose whose delay modulo
> > 1000ms is greater than 900 are highly likely to be affected (there's a
> > good chance their delay was too small before).
> >
> > BUG=587074
> >
> > Committed: https://crrev.com/b56bbe4ce3e7276a130a00d83cf00e5672cd6be1
> > Cr-Commit-Position: refs/heads/master@{#376993}
>
> TBR=skyostil@chromium.org,alexclarke@chromium.org
> # Not skipping CQ checks because original CL landed more than 1 days ago.
> BUG=587074
>
> Committed: https://crrev.com/7a1d629da81d8218afbf86eb4ff6c977970cd8d4
> Cr-Commit-Position: refs/heads/master@{#377995}

TBR=skyostil@chromium.org,alexclarke@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=587074

Committed: https://crrev.com/cbfca553a3472a95aea36848988ac0dc3167e684
Cr-Commit-Position: refs/heads/master@{#378026}
==========

[commit-bot: I haz the power, 2016-02-26 23:52:22]

Patchset 1 (id:??) landed as
https://crrev.com/cbfca553a3472a95aea36848988ac0dc3167e684
Cr-Commit-Position: refs/heads/master@{#378026}