Add initial code for verifying a certificate chain.

net/net.gypi

Index: net/net.gypi
diff --git a/net/net.gypi b/net/net.gypi
index b8d4ce0ef99910869de15bf343a60f4785c3e320..88969827e94ff01d63ffc30a8079302e8e0f7f83 100644
--- a/net/net.gypi
+++ b/net/net.gypi
@@ -105,6 +105,8 @@
       'cert/internal/verify_name_match.h',
       'cert/internal/verify_signed_data.cc',
       'cert/internal/verify_signed_data.h',
+      'cert/internal/verify_certificate_chain.cc',
+      'cert/internal/verify_certificate_chain.h',
       'cert/pem_tokenizer.cc',
       'cert/pem_tokenizer.h',
       'cert/sha256_legacy_support_win.cc',
@@ -1337,6 +1339,7 @@
       'cert/internal/signature_algorithm_unittest.cc',
       'cert/internal/test_helpers.cc',
       'cert/internal/test_helpers.h',
+      'cert/internal/verify_certificate_chain_unittest.cc',
       'cert/internal/verify_name_match_unittest.cc',
       'cert/internal/verify_signed_data_unittest.cc',
       'cert/jwk_serializer_unittest.cc',