gn docs: Update toolchain example in the language reference

gn docs: Update toolchain example in the language reference

Since https://codereview.chromium.org/2219083002 the syntax for
declaring toolchain arguments has changed, so update the
example:
- Use toolchain_args = {} instead of toolchain_args() {}
- Use current_cpu instead of toolchain_cpu.

R=brettw@chromium.org,dpranke@chromium.org
BUG=634446
Committed: https://crrev.com/fe6025a7bcbba301acfe8a049c44b17f0b19efd5
Cr-Commit-Position: refs/heads/master@{#426228}

[Dirk Pranke, 2016-10-19 16:39:38]

lgtm, thanks!

[Raphael Kubo da Costa (rakuco), 2016-10-19 16:45:01]

The CQ bit was checked by raphael.kubo.da.costa@intel.com

[commit-bot: I haz the power, 2016-10-19 16:45:25]

CQ is trying da patch. Follow status at
 
https://chromium-cq-status.appspot.com/v2/patch-status/codereview.chromium.or...

[commit-bot: I haz the power, 2016-10-19 17:07:00]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2016-10-21 13:09:35]

Description was changed from

==========
gn docs: Update toolchain example in the language reference

Since https://codereview.chromium.org/2219083002 the syntax for
declaring toolchain arguments has changed, so update the
example:
- Use toolchain_args = {} instead of toolchain_args() {}
- Use current_cpu instead of toolchain_cpu.

R=brettw@chromium.org,dpranke@chromium.org
BUG=634446
==========

to

==========
gn docs: Update toolchain example in the language reference

Since https://codereview.chromium.org/2219083002 the syntax for
declaring toolchain arguments has changed, so update the
example:
- Use toolchain_args = {} instead of toolchain_args() {}
- Use current_cpu instead of toolchain_cpu.

R=brettw@chromium.org,dpranke@chromium.org
BUG=634446

Committed: https://crrev.com/fe6025a7bcbba301acfe8a049c44b17f0b19efd5
Cr-Commit-Position: refs/heads/master@{#426228}
==========

[commit-bot: I haz the power, 2016-10-21 13:09:36]

Patchset 1 (id:??) landed as
https://crrev.com/fe6025a7bcbba301acfe8a049c44b17f0b19efd5
Cr-Commit-Position: refs/heads/master@{#426228}