Create stubs for system certificate validation.

net/net.gyp

Index: net/net.gyp
diff --git a/net/net.gyp b/net/net.gyp
index f105fe62be95f954e654fff412d6c06b3f23fce7..53b5002fab1588211bff0f5baf2a2ac0b3548459 100644
--- a/net/net.gyp
+++ b/net/net.gyp
@@ -70,6 +70,14 @@
         'base/cert_status_flags.h',
         'base/cert_verifier.cc',
         'base/cert_verifier.h',
+        'base/cert_verify_proc_mac.cc',
+        'base/cert_verify_proc_mac.h',
+        'base/cert_verify_proc_nss.cc',
+        'base/cert_verify_proc_nss.h',
+        'base/cert_verify_proc_openssl.cc',
+        'base/cert_verify_proc_openssl.h',
+        'base/cert_verify_proc_win.cc',
+        'base/cert_verify_proc_win.h',
         'base/cert_verify_result.cc',
         'base/cert_verify_result.h',
         'base/completion_callback.h',
@@ -848,6 +856,8 @@
           {  # else !use_openssl: remove the unneeded files
             'sources!': [
               'base/cert_database_openssl.cc',
+              'base/cert_verify_proc_openssl.cc',
+              'base/cert_verify_proc_openssl.h',
               'base/crypto_module_openssl.cc',
               'base/keygen_handler_openssl.cc',
               'base/openssl_memory_private_key_store.cc',
@@ -923,6 +933,12 @@
             '../build/linux/system.gyp:gdk',
           ],
         }],
+        [ 'use_nss!=1', {

[wtc, 2012/03/06 23:10:14]

Nit: the neighboring code uses spaces around == and !=,
so it would be nice to follow the style.

+            'sources!': [
+              'base/cert_verify_proc_nss.cc',
+              'base/cert_verify_proc_nss.h',
+            ],
+        }],
         [ 'OS == "win"', {
             'sources!': [
               'http/http_auth_handler_ntlm_portable.cc',