[Cast Channel] Add support for nonce challenge to Cast channel authentication.

extensions/browser/api/cast_channel/cast_auth_util.h

Index: extensions/browser/api/cast_channel/cast_auth_util.h
diff --git a/extensions/browser/api/cast_channel/cast_auth_util.h b/extensions/browser/api/cast_channel/cast_auth_util.h
index 1f66395413963a1ea21c95dc40503927dcaf36da..ebc47dea0fb69ff426a5b7f7965ce6bc8097b985 100644
--- a/extensions/browser/api/cast_channel/cast_auth_util.h
+++ b/extensions/browser/api/cast_channel/cast_auth_util.h
@@ -46,6 +46,7 @@ struct AuthResult {
     ERROR_TLS_CERT_EXPIRED,
     ERROR_CRL_INVALID,
     ERROR_CERT_REVOKED,
+    ERROR_SENDER_NONCE_MISMATCH,
   };
 
   enum PolicyType { POLICY_NONE = 0, POLICY_AUDIO_ONLY = 1 << 0 };
@@ -71,7 +72,8 @@ struct AuthResult {
 // 1. Signature contained in the reply is valid.
 // 2. Certficate used to sign is rooted to a trusted CA.
 AuthResult AuthenticateChallengeReply(const CastMessage& challenge_reply,
-                                      const net::X509Certificate& peer_cert);
+                                      const net::X509Certificate& peer_cert,
+                                      const std::string& nonce);
 
 // Auth-library specific implementation of cryptographic signature
 // verification routines. Verifies that |response| contains a