win gn: Semi-support for non-depot_tools toolchain

win gn: Semi-support for non-depot_tools toolchain

I had to set:

DEPOT_TOOLS_WIN_TOOLCHAIN=0
GYP_MSVS_OVERRIDE_PATH=C:/Program Files (x86)/Microsoft Visual Studio 12.0
GYP_MSVS_VERSION=2013
WindowsSdkDir=C:/Program Files (x86)/Windows Kits/8.1

then

gn gen out\gn --args="is_debug=true cpu_arch=\"x86\""
ninja -C out/gn base

worked OK.

Further patches welcome to make this less ugly.

R=dpranke@chromium.org

Committed: https://crrev.com/fa5da3e4e515967d593c3822b1d82f5e844080c5
Cr-Commit-Position: refs/heads/master@{#307791}

[scottmg, 2014-12-10 20:01:37]

scottmg@chromium.org changed reviewers:
+ vyacheslav.chigrin@yandex.ru

[Dirk Pranke, 2014-12-10 20:36:05]

better than it was before, at least :).

lgtm.

[scottmg, 2014-12-10 20:36:48]

The CQ bit was checked by scottmg@chromium.org

[scottmg, 2014-12-10 20:37:49]

Yeah. We need to pull in quite a bit of gyp code to do it properly, so I'd
rather come up with a better way, get a bot that does this, etc.

[commit-bot: I haz the power, 2014-12-10 20:37:52]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/789303002/40001

[commit-bot: I haz the power, 2014-12-10 20:52:56]

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

[commit-bot: I haz the power, 2014-12-10 20:52:57]

Try jobs failed on following builders:
  chromium_presubmit on tryserver.chromium.linux
(http://build.chromium.org/p/tryserver.chromium.linux/builders/chromium_presub...)

[scottmg, 2014-12-10 20:55:16]

scottmg@chromium.org changed reviewers:
+ brettw@chromium.org

[scottmg, 2014-12-10 20:55:37]

+brettw as build/toolchain is noparent.

[brettw, 2014-12-10 22:49:29]

lgtm

[scottmg, 2014-12-10 22:59:40]

The CQ bit was checked by scottmg@chromium.org

[commit-bot: I haz the power, 2014-12-10 23:01:38]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/789303002/40001

[commit-bot: I haz the power, 2014-12-10 23:34:18]

Committed patchset #3 (id:40001)

[commit-bot: I haz the power, 2014-12-10 23:35:11]

Patchset 3 (id:??) landed as
https://crrev.com/fa5da3e4e515967d593c3822b1d82f5e844080c5
Cr-Commit-Position: refs/heads/master@{#307791}