Enable implicit auto-upgrade to python 2.7.5.

Enable implicit auto-upgrade to python 2.7.5.

This will automatically upgrade python to 2.7.5 unless
set DEPOT_TOOLS_PYTHON_275=0
is used.

R=iannucci@chromium.org
BUG=241769
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=235140

[M-A Ruel, 2013-10-30 20:33:50]

One annoying thing is that it's doing it at large in one shot. One thing that I
can do is go on all the windows slaves manually and install python 2.7.5 on each
of them.

[iannucci, 2013-10-30 20:43:29]

On 2013/10/30 20:33:50, M-A Ruel wrote:
> One annoying thing is that it's doing it at large in one shot. One thing that
I
> can do is go on all the windows slaves manually and install python 2.7.5 on
each
> of them.

Yikes! This seems scary...

Could we do a dumb thing and inspect the buildbot buildername env var, and then
roll it out one builder at a time, and then after that works, enable it for
everything else?

[M-A Ruel, 2013-11-13 19:24:02]

On 2013/10/30 20:43:29, iannucci wrote:
> On 2013/10/30 20:33:50, M-A Ruel wrote:
> > One annoying thing is that it's doing it at large in one shot. One thing
that
> I
> > can do is go on all the windows slaves manually and install python 2.7.5 on
> each
> > of them.
> 
> Yikes! This seems scary...
> 
> Could we do a dumb thing and inspect the buildbot buildername env var, and
then
> roll it out one builder at a time, and then after that works, enable it for
> everything else?

Rolled out manually, I'm ready to commit.

[iannucci, 2013-11-13 20:22:42]

lgtm, good luck... probably worth a note to chromium-dev for windows developers?

[M-A Ruel, 2013-11-14 15:05:03]

Committed patchset #1 manually as r235140.