Revert "Add disable_goma for args.gn on win"

This reverts commit 953fcf3fe08d99068f2a4b39081a2ab55dae178a.

Reason for revert: We want to set envvar directly.

Original change's description:
> Add disable_goma for args.gn on win
>
> Switching use_goma causes full rebuild due to command line update in build.ninja.
> I added disable_goma to set GOMA_DISABLED on environment.{x86,x64}.
>
> If we specify disable_goma=true, GOMA_DISABLED env is passed to gomacc.
> Then gomacc executes given argument instead of sending args to goma daemon.
>
> This will help toolchain maintainer to check difference of build behavior w/wo goma without rebuilding everything.
>
> Bug:
> Change-Id: Ie58958b5484d57be1c40fbbca363f1eef4b55c7e
> Reviewed-on: https://chromium-review.googlesource.com/768549
> Reviewed-by: Dirk Pranke <dpranke@chromium.org>
> Reviewed-by: Bruce Dawson <brucedawson@chromium.org>
> Commit-Queue: Takuto Ikuta <tikuta@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#518134}

TBR=dpranke@chromium.org,brucedawson@chromium.org,tikuta@chromium.org

Change-Id: Ia2d510f4149b30cff3f8dc6c0b89e37190c39368
Reviewed-on: https://chromium-review.googlesource.com/1015860
Reviewed-by: Nico Weber <thakis@chromium.org>
Commit-Queue: Takuto Ikuta <tikuta@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#551602}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: ee4c20c2074018c75d297647820d1d58f82fd7c9
3 files changed