win: pull gyp for gn generation

win: pull gyp for gn generation

and #if out some code that causes "unreachable code" warning on windows.

TBR=jam@chromium.org
BUG=

Committed: https://chromium.googlesource.com/external/mojo/+/8f63fa97b4593f77d240d346efd78773827b539c

[scottmg, 2014-11-07 17:32:36]

pull gyp replaces the build/ changes in previous attempts. looks like other
things were broken in the gn build since last build (zlib is the first one i
saw)

[scottmg, 2014-11-07 17:58:29]

Committed patchset #1 (id:1) manually as
8f63fa97b4593f77d240d346efd78773827b539c.

[jamesr, 2014-11-07 18:01:17]

jamesr@chromium.org changed reviewers:
+ jamesr@chromium.org

[jamesr, 2014-11-07 18:01:17]

Why do you have to pull gyp?

[scottmg, 2014-11-07 18:20:12]

On 2014/11/07 18:01:17, jamesr wrote:
> Why do you have to pull gyp?

GN uses the internals of gyp still (shelling to python scripts, etc.) to set up
toolchains.

[jamesr, 2014-11-07 18:22:21]

Yeah but that's a bug that needs to be fixed in chromium as well, right?

[scottmg, 2014-11-07 18:25:27]

On 2014/11/07 18:22:21, jamesr wrote:
> Yeah but that's a bug that needs to be fixed in chromium as well, right?

I guess, but it's not going to get changed any time soon.