Updating D2D protocol to v1 to support separate sequence numbers.

components/cryptauth/device_to_device_responder_operations.h

Index: components/cryptauth/device_to_device_responder_operations.h
diff --git a/components/cryptauth/device_to_device_responder_operations.h b/components/cryptauth/device_to_device_responder_operations.h
index 6e16db1787d85983c0129fed458697d0a33dd3e0..b0ebf677c3f6ee22449c81aab7f6a3a8bbb06d3a 100644
--- a/components/cryptauth/device_to_device_responder_operations.h
+++ b/components/cryptauth/device_to_device_responder_operations.h
@@ -13,6 +13,7 @@
 namespace cryptauth {
 
 class SecureMessageDelegate;
+class SessionKeys;
 
 // Utility class containing operations in the DeviceToDevice protocol that the
 // initiator needs to perform. For Smart Lock, in which a phone unlocks a
@@ -92,8 +93,7 @@ class DeviceToDeviceResponderOperations {
   // is properly signed and encrypted.
   // |initiator_auth_message|: The bytes of the [Local Auth] message to
   // validate.
-  // |session_symmetric_key|: The derived symmetric key used just for the
-  //     session.
+  // |session_keys|: The derived symmetric keys used just for the session.
   // |persistent_symmetric_key|: The long-term symmetric key that is shared by
   //     the initiator and responder.
   // |secure_message_delegate|: Delegate for SecureMessage operations. This
@@ -102,7 +102,7 @@ class DeviceToDeviceResponderOperations {
   //     |responder_auth_message| is validated successfully.
   static void ValidateInitiatorAuthMessage(
       const std::string& initiator_auth_message,
-      const std::string& session_symmetric_key,
+      SessionKeys* session_keys,
       const std::string& persistent_symmetric_key,
       const std::string& responder_auth_message,
       SecureMessageDelegate* secure_message_delegate,