Enable passing cast channel certificate authority keys.

net/cert/x509_certificate.h

Index: net/cert/x509_certificate.h
diff --git a/net/cert/x509_certificate.h b/net/cert/x509_certificate.h
index 97906ed0461f02c4d8705e2e3db8109484f21f1b..97711add0aa152463c672fbc8943064fa74f4c83 100644
--- a/net/cert/x509_certificate.h
+++ b/net/cert/x509_certificate.h
@@ -217,6 +217,12 @@ class NET_EXPORT X509Certificate
   // The fingerprint of this certificate.
   const SHA1HashValue& fingerprint() const { return fingerprint_; }
 
+  // The SHA-256 fingerprint of this certificate.
+  const SHA256HashValue fingerprint256() const {
+    net::X509Certificate::OSCertHandles intermediate;
+    return CalculateChainFingerprint256(os_cert_handle(), intermediate);
+  }
+
   // The fingerprint of the intermediate CA certificates.
   const SHA1HashValue& ca_fingerprint() const {
     return ca_fingerprint_;