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

Revert of Revert of Revert of Fixit: Factor out common base::Time* math operator overloads. (patchset #1 id:1 of https://codereview.chromium.org/1128273004/)

Reason for revert:
Still breaks iOS bots. Tracking at crbug.com/485435.

Original issue's description:
> 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}

TBR=thestig@chromium.org,ksakamoto@chromium.org,smut@chromium.org,miu@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=467417, 485435
Committed: https://crrev.com/5025b5bd30daed552c65b3b7c0c0c03b9d360699
Cr-Commit-Position: refs/heads/master@{#328864}

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

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

[commit-bot: I haz the power, 2015-05-07 22:34:18]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1125283003/1

[commit-bot: I haz the power, 2015-05-07 22:37:08]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2015-05-07 22:38:10]

Patchset 1 (id:??) landed as
https://crrev.com/5025b5bd30daed552c65b3b7c0c0c03b9d360699
Cr-Commit-Position: refs/heads/master@{#328864}