Revert of Revert of Fixit: Factor out common base::Time* math operator overloads.

Revert of Revert of Fixit: Factor out common base::Time* math operator overloads. (patchset #1 id:1 of https://codereview.chromium.org/1130953002/)

Reason for revert:
iOS_Device builder was not rebuilding certain modules dependent on changes in base::Time.  http://crbug.com/485435

Original issue's description:
> Revert of Fixit: Factor out common base::Time* math operator overloads. (patchset #2 id:40001 of https://codereview.chromium.org/1122443004/)
>
> Reason for revert:
> Broke iOS build.
>
> http://build.chromium.org/p/chromium.mac/builders/iOS_Device/builds/5621/steps/compile/logs/stdio
>
> Original issue's description:
> > Fixit: Factor out common base::Time* math operator overloads.
> >
> > This is part 1 of a 2-part change to fork base::TimeTicks into three
> > type-checked time classes (TimeTicks + ThreadTicks + TraceTicks).  The
> > forking of TimeTicks will ensure values from different clocks are not
> > erroneously being mixed together when doing time math.
> >
> > In this change, the identical comparison and math operator overloads
> > found in base::Time and base::TimeTicks are being factored-out into a
> > templated base class.  In a following change, this base class will also
> > be used to de-dupe this common functionality in the two new time
> > classes.
> >
> > BUG=467417
> >
> > Committed: https://crrev.com/7ca717095b4758cb76e53e904b775852e46d646d
> > Cr-Commit-Position: refs/heads/master@{#328696}
>
> TBR=thestig@chromium.org,miu@chromium.org
> NOPRESUBMIT=true
> NOTREECHECKS=true
> NOTRY=true
> BUG=467417
>
> Committed: https://crrev.com/a365825583412c355a449274bec70e41e992ffd7
> Cr-Commit-Position: refs/heads/master@{#328706}

TBR=thestig@chromium.org,ksakamoto@chromium.org
NOPRESUBMIT=true
BUG=467417, 485435
Committed: https://crrev.com/59fca1cd30487a013b942acf9d660dfcc639e25a
Cr-Commit-Position: refs/heads/master@{#328843}

[miu, 2015-05-07 04:56:29]

Created Revert of Revert of Fixit: Factor out common base::Time* math operator
overloads.

[miu, 2015-05-07 05:30:39]

Sorry for the spam.  I created a revert to re-run the iOS trybots.

I suspect the iOS_Device builder is busted.

[miu, 2015-05-07 18:36:23]

miu@chromium.org changed reviewers:
+ smut@chromium.org

[miu, 2015-05-07 18:37:29]

Okay, I'm going to land this revert-of-revert, but will have it go through the
CQ to be extra sure.  The reason for the original revert was due to a builder
problem.  I've referenced the relevant bug in the description.

[miu, 2015-05-07 18:37:37]

The CQ bit was checked by miu@chromium.org

[commit-bot: I haz the power, 2015-05-07 18:40:36]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1128273004/1

[miu, 2015-05-07 18:56:01]

...and once again, I see the iOS bots are green for this change (in the CQ).

[commit-bot: I haz the power, 2015-05-07 21:42:17]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-05-07 21:44:50]

Patchset 1 (id:??) landed as
https://crrev.com/59fca1cd30487a013b942acf9d660dfcc639e25a
Cr-Commit-Position: refs/heads/master@{#328843}

[Garrett Casto, 2015-05-07 22:30:33]

A revert of this CL (patchset #1 id:1) has been created in
https://codereview.chromium.org/1125283003/ by gcasto@chromium.org.

The reason for reverting is: Still breaks iOS bots. Tracking at
crbug.com/485435..