Create stubs for system certificate validation.

net/net.gyp

Index: net/net.gyp
diff --git a/net/net.gyp b/net/net.gyp
index d205895092ee3e8b03d80953aa69f3b7f87827d6..8bf4cd3c807d85db27b6f559751eb8c5b0b75c0b 100644
--- a/net/net.gyp
+++ b/net/net.gyp
@@ -70,6 +70,16 @@
         'base/cert_status_flags.h',
         'base/cert_verifier.cc',
         'base/cert_verifier.h',
+        'base/cert_verify_proc.cc',
+        'base/cert_verify_proc.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',
@@ -819,6 +829,8 @@
         ['use_openssl==1', {
             'sources!': [
               'base/cert_database_nss.cc',
+              'base/cert_verify_proc_nss.cc',
+              'base/cert_verify_proc_nss.h',
               'base/crypto_module_nss.cc',
               'base/dnssec_keyset.cc',
               'base/dnssec_keyset.h',
@@ -850,6 +862,8 @@
           {  # 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',
@@ -925,6 +939,12 @@
             '../build/linux/system.gyp:gdk',
           ],
         }],
+        [ 'use_nss != 1', {
+            'sources!': [
+              'base/cert_verify_proc_nss.cc',
+              'base/cert_verify_proc_nss.h',
+            ],
+        }],
         [ 'OS == "win"', {
             'sources!': [
               'http/http_auth_handler_ntlm_portable.cc',