Update Jinja2 (Python template library) to 2.7.1

Update Jinja2 (Python template library) to 2.7.1

Jinja2 (used in Blink scripts in Source/core and Source/bindings) has
been updated to 2.7.1 (from existing 2.6); see changelog.
http://jinja.pocoo.org/docs/changelog/

The specific new features in this release that are useful are:
* keep_trailing_newline
* lstrip_blocks
...which make it easier to control whitespace, making templates easier to read.
(Specifically it lets us easily indent control blocks.)
* selectattr (allows filtering lists in template, simplifying Python code)

In the Changelog these are referred to as:
Added support for keeping the trailing newline in templates.
Added finer grained support for stripping whitespace on the left side of blocks.
Added map, select, reject, selectattr and rejectattr filters.

BTW, 2.7 is the first Jinja2 major release in 2 years;
2.7.1 is a bugfix release:
2.7   2013-05-20
2.7.1 2013-08-07

This upgrade introduces a new dependency (on Windows), due to the safe string class being factored out into a separate library.
Thus depends on separate CL:
Add MarkupSafe library to third_party (dependency for Jinja2 2.7)
https://codereview.chromium.org/23445019/
This has been committed as r221578:
https://src.chromium.org/viewvc/chrome?view=rev&revision=221578

TBR=cpu@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=221663

[Nils Barth (inactive), 2013-08-27 06:14:06]

Brett, Carlos,
Need third_party OWNERS approval for this update;
I'm also adding package-specific OWNERS so you won't need to
be bothered in future.
Could you please take a look?
Should be routine, as it's just an update.

Tim: I've added you to OWNERS as you originated this library
and are using it in core.

haraken: this will help make our templates a bit more readable
(plus bugfixes); I'll make changes once this has rolled.

[cpu_(ooo_6.6-7.5), 2013-08-27 17:36:47]

no need for approval, see the owners file in third_party for instructions.

[Nils Barth (inactive), 2013-08-28 01:52:41]

On 2013/08/27 17:36:47, cpu wrote:
> no need for approval, see the owners file in third_party for instructions.

Thanks Carlos!
So I just need at l.g.t.m from you or someone, right, per instructions?
If it's ok, could you check the box?
Thanks!

# Owner approval for 3rd party is only required for
# adding new libraries. For changes to existing code
# simply TBR= one of people below.

[haraken, 2013-08-28 01:58:44]

LGTM as an OWNER of bindings/, which is the customer of the library.

You can TBR= one of the third party owners and land it.

[Nils Barth (inactive), 2013-08-28 03:29:47]

On 2013/08/28 01:58:44, haraken wrote:
> LGTM as an OWNER of bindings/, which is the customer of the library.
> 
> You can TBR= one of the third party owners and land it.

Thanks!
Asked Carlos (as TBR) -- now to wait for the world to spin.

[Nils Barth (inactive), 2013-08-29 01:11:22]

ping Brett, Carlos - PTAL
(need an L.G.T.M from third_party b/c no dir-specific OWNERS yet)

[Nils Barth (inactive), 2013-08-30 01:28:18]

Hi Brett, Carlos, or Darin,

Updating a third_party library (which has no OWNERS file,
hence I need approval from one of you),
and adding an OWNERS file so we won't need to bother you in future!
Is this ok? (Should be routine.)

Thanks,
Nils

[commit-bot: I haz the power, 2013-08-30 01:29:19]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/nbarth@chromium.org/23506004/2001

[Nils Barth (inactive), 2013-08-30 01:41:00]

Sorry OWNERS, just understood TBR (= don't need a priori approval) - submitting.

[commit-bot: I haz the power, 2013-08-30 02:07:57]

Sorry for I got bad news for ya.
Compile failed with a clobber build on win.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win&number...
Your code is likely broken or HEAD is junk. Please ensure your
code is not broken then alert the build sheriffs.
Look at the try server FAQ for more details.

[Nils Barth (inactive), 2013-08-30 05:06:04]

On 2013/08/30 02:07:57, I haz the power (commit-bot) wrote:
> Sorry for I got bad news for ya.
> Compile failed with a clobber build on win.

Turns out there's a new dependency, because the string class was factored out
into a separate library, and this isn't included by default on Windows.

"As of version 2.7 Jinja2 depends on the MarkupSafe module."
http://jinja.pocoo.org/docs/intro/#markupsafe-dependency

Opened a separate issue to add it.

Add MarkupSafe library to third_party (dependency for Jinja2 2.7)
https://codereview.chromium.org/23445019/

[commit-bot: I haz the power, 2013-09-06 05:31:13]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/nbarth@chromium.org/23506004/31001

[commit-bot: I haz the power, 2013-09-06 09:48:36]

Change committed as 221663