Add ability to pass decryption key id to CreateSecureMessage method

chrome/common/extensions/api/easy_unlock_private.idl

Index: chrome/common/extensions/api/easy_unlock_private.idl
diff --git a/chrome/common/extensions/api/easy_unlock_private.idl b/chrome/common/extensions/api/easy_unlock_private.idl
index 5a33e5e26457c0396b4b87bca1bab50e21dd725d..6766a00d61d852264fae622f1f2391fee133181c 100644
--- a/chrome/common/extensions/api/easy_unlock_private.idl
+++ b/chrome/common/extensions/api/easy_unlock_private.idl
@@ -77,11 +77,15 @@
     ArrayBuffer? publicMetadata;
 
     // Verification key id added to the message header. Should be set if the
-    // message is signed using |ECDSA_P256_SHA256|. It's used by the message
+    // message is signed using |ECDSA_P256_SHA256|. Used by the message
     // recepient to determine which key should be used to verify the message
     // signature.
     ArrayBuffer? verificationKeyId;
 
+    // Decryption key id added to the message header. Used by the message
+    // recepient to determine which key should be used to decrypt the message.
+    ArrayBuffer? decryptionKeyId;
+
     // The encryption algorithm that should be used to encrypt the message.
     // Should not be set for a cleartext message.
     EncryptionType? encryptType;