Switch MB to write the GN args to args.gn.

Switch MB to write the GN args to args.gn.

This CL switches MB from passing the gn arguments on the
command line via --args to actually writing them to an
args.gn file. This makes some of the escaping slightly cleaner
and also will enable us to embed import() lines in a follow-on
CL, so that we can use //build/args templates.

R=brettw@chromium.org
BUG=602528
Committed: https://crrev.com/eca4a786d114c8a36583503f3d251a37dcffa023
Cr-Commit-Position: refs/heads/master@{#387205}

[Dirk Pranke, 2016-04-12 18:06:49]

https://codereview.chromium.org/1880903002/diff/1/build/gn_helpers.py
File build/gn_helpers.py (right):

https://codereview.chromium.org/1880903002/diff/1/build/gn_helpers.py#newcode54
build/gn_helpers.py:54: for key in sorted(value):
this makes things a little more deterministic and sensible.

[brettw, 2016-04-12 21:46:04]

lgtm

https://codereview.chromium.org/1880903002/diff/1/build/gn_helpers.py
File build/gn_helpers.py (right):

https://codereview.chromium.org/1880903002/diff/1/build/gn_helpers.py#newcode27
build/gn_helpers.py:27: """Prints the given value to stdout.
While you're here can you fix this line? It returns a string that GN can read
instead of printing it.

[Dirk Pranke, 2016-04-12 21:47:52]

https://codereview.chromium.org/1880903002/diff/1/build/gn_helpers.py
File build/gn_helpers.py (right):

https://codereview.chromium.org/1880903002/diff/1/build/gn_helpers.py#newcode27
build/gn_helpers.py:27: """Prints the given value to stdout.
On 2016/04/12 21:46:03, brettw wrote:
> While you're here can you fix this line? It returns a string that GN can read
> instead of printing it.

Sure.

[Dirk Pranke, 2016-04-13 19:19:52]

The CQ bit was checked by dpranke@chromium.org

[Dirk Pranke, 2016-04-13 19:19:53]

The patchset sent to the CQ was uploaded after l-g-t-m from brettw@chromium.org
Link to the patchset: https://codereview.chromium.org/1880903002/#ps20001
(title: "fix doc string per review")

[commit-bot: I haz the power, 2016-04-13 19:20:05]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1880903002/20001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1880903002/20001

[commit-bot: I haz the power, 2016-04-13 19:27:25]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2016-04-13 19:27:26]

Try jobs failed on following builders:
  ios_rel_device_gn on tryserver.chromium.mac (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.mac/builders/ios_rel_device_gn...)

[Dirk Pranke, 2016-04-14 00:38:56]

The CQ bit was checked by dpranke@chromium.org

[Dirk Pranke, 2016-04-14 00:38:57]

The patchset sent to the CQ was uploaded after l-g-t-m from brettw@chromium.org
Link to the patchset: https://codereview.chromium.org/1880903002/#ps40001
(title: "fix unicode handling in gn_helpers")

[commit-bot: I haz the power, 2016-04-14 00:39:36]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/1880903002/40001
View timeline at
 https://chromium-cq-status.appspot.com/patch-timeline/1880903002/40001

[commit-bot: I haz the power, 2016-04-14 01:42:53]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2016-04-14 01:44:22]

Description was changed from

==========
Switch MB to write the GN args to args.gn.

This CL switches MB from passing the gn arguments on the
command line via --args to actually writing them to an
args.gn file. This makes some of the escaping slightly cleaner
and also will enable us to embed import() lines in a follow-on
CL, so that we can use //build/args templates.

R=brettw@chromium.org
BUG=602528
==========

to

==========
Switch MB to write the GN args to args.gn.

This CL switches MB from passing the gn arguments on the
command line via --args to actually writing them to an
args.gn file. This makes some of the escaping slightly cleaner
and also will enable us to embed import() lines in a follow-on
CL, so that we can use //build/args templates.

R=brettw@chromium.org
BUG=602528

Committed: https://crrev.com/eca4a786d114c8a36583503f3d251a37dcffa023
Cr-Commit-Position: refs/heads/master@{#387205}
==========

[commit-bot: I haz the power, 2016-04-14 01:44:23]

Patchset 3 (id:??) landed as
https://crrev.com/eca4a786d114c8a36583503f3d251a37dcffa023
Cr-Commit-Position: refs/heads/master@{#387205}