Update Simulcrypt ECMg

common/rot_id_util.h

@@ -21,6 +21,14 @@
 
 namespace widevine {
 
+// Helper function that generates the unique id hash from the |unique_id| and
+// the |salt|. |salt| is an internal secret.
+//
+// Returns the hash value on success.
+// If |salt| or |unique_id| are empty, this will return an empty string.
+std::string GenerateUniqueIdHash(const std::string& unique_id,
+                                 const std::string& salt);
+
 // Helper function that generates the hash for the ROT id from the
 // |unique_id_hash|, the |system_id| and the |salt|. |salt| is typically an
 // encrypted unique id. Since we use an ephemeral eliptic curve key as part of