Use SPNEGO mechanism with GSSAPI on Posix

net/http/http_auth_gssapi_posix.h

Index: net/http/http_auth_gssapi_posix.h
diff --git a/net/http/http_auth_gssapi_posix.h b/net/http/http_auth_gssapi_posix.h
index 96c7176b14af5bfa7c9bc32411e2091674267dc9..93c9400ea451d741d06b6ceca2f5fb300f98c806 100644
--- a/net/http/http_auth_gssapi_posix.h
+++ b/net/http/http_auth_gssapi_posix.h
@@ -17,9 +17,8 @@
 
 namespace net {
 
-NET_EXPORT_PRIVATE extern gss_OID CHROME_GSS_C_NT_HOSTBASED_SERVICE_X;
-NET_EXPORT_PRIVATE extern gss_OID CHROME_GSS_C_NT_HOSTBASED_SERVICE;
-NET_EXPORT_PRIVATE extern gss_OID CHROME_GSS_KRB5_MECH_OID_DESC;
+// Mechanism OID for GSSAPI. We always use SPNEGO.
+NET_EXPORT_PRIVATE extern gss_OID CHROME_GSS_SPNEGO_MECH_OID_DESC;
 
 // GSSAPILibrary is introduced so unit tests can mock the calls to the GSSAPI
 // library. The default implementation attempts to load one of the standard