Fix chromium.gyp_env to see GYP_MSVS_VERSION.

Fix from scottmg.

[email protected]

Review URL: https://codereview.chromium.org/136663004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@244585 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/build/gyp_helper.py b/build/gyp_helper.py
index 8124278..eadc7a5f 100644
--- a/build/gyp_helper.py
+++ b/build/gyp_helper.py
@@ -34,6 +34,7 @@
       'GYP_CROSSCOMPILE',
       'GYP_GENERATOR_OUTPUT',
       'GYP_GENERATORS',
+      'GYP_MSVS_VERSION',
   )
   for var in supported_vars:
     file_val = file_data.get(var)