Extract IsKnownRoot() functionality for testing if a certificate is a

net/BUILD.gn

Index: net/BUILD.gn
diff --git a/net/BUILD.gn b/net/BUILD.gn
index b2e1f4d7b016c5c51689dd0a885c61a9ae7663cd..2bacaf0571597cc393e827ce072cc36aa3e4b915 100644
--- a/net/BUILD.gn
+++ b/net/BUILD.gn
@@ -567,6 +567,12 @@ component("net") {
       "cert/internal/trust_store_nss.h",
       "cert/jwk_serializer.cc",
       "cert/jwk_serializer.h",
+      "cert/known_roots_mac.cc",
+      "cert/known_roots_mac.h",
+      "cert/known_roots_nss.cc",
+      "cert/known_roots_nss.h",
+      "cert/known_roots_win.cc",
+      "cert/known_roots_win.h",
       "cert/merkle_audit_proof.cc",
       "cert/merkle_audit_proof.h",
       "cert/merkle_consistency_proof.cc",
@@ -1807,6 +1813,8 @@ component("net") {
         "cert/internal/cert_issuer_source_nss.h",
         "cert/internal/trust_store_nss.cc",
         "cert/internal/trust_store_nss.h",
+        "cert/known_roots_nss.cc",
+        "cert/known_roots_nss.h",
         "cert/nss_cert_database.cc",
         "cert/nss_cert_database.h",
         "cert/x509_certificate_nss.cc",