Removed GPR_POSIX_FILE, and changed the files that used it
diff --git a/binding.gyp b/binding.gyp
index a078e5c..b03da7c 100644
--- a/binding.gyp
+++ b/binding.gyp
@@ -682,8 +682,7 @@
'src/core/lib/security/credentials/credentials.c',
'src/core/lib/security/credentials/credentials_metadata.c',
'src/core/lib/security/credentials/fake/fake_credentials.c',
- 'src/core/lib/security/credentials/google_default/credentials_posix.c',
- 'src/core/lib/security/credentials/google_default/credentials_windows.c',
+ 'src/core/lib/security/credentials/google_default/credentials_generic.c',
'src/core/lib/security/credentials/google_default/google_default_credentials.c',
'src/core/lib/security/credentials/iam/iam_credentials.c',
'src/core/lib/security/credentials/jwt/json_token.c',