Revert of Auth work to support new auth protocol

chrome/browser/extensions/api/cast_channel/cast_channel.proto

Index: chrome/browser/extensions/api/cast_channel/cast_channel.proto
diff --git a/chrome/browser/extensions/api/cast_channel/cast_channel.proto b/chrome/browser/extensions/api/cast_channel/cast_channel.proto
index fd226541d5abdf22730b462ec9de946aa9b021d4..d321eaf8ad6c3a69b90fd5bbd436dcefe254e6ad 100644
--- a/chrome/browser/extensions/api/cast_channel/cast_channel.proto
+++ b/chrome/browser/extensions/api/cast_channel/cast_channel.proto
@@ -53,31 +53,19 @@
   optional bytes payload_binary = 7;
 }
 
-enum SignatureAlgorithm {
-  UNSPECIFIED = 0;
-  RSASSA_PKCS1v15 = 1;
-  RSASSA_PSS = 2;
-}
-
 // Messages for authentication protocol between a sender and a receiver.
 message AuthChallenge {
-  optional SignatureAlgorithm signature_algorithm = 1
-      [default = RSASSA_PKCS1v15];
 }
 
 message AuthResponse {
   required bytes signature = 1;
   required bytes client_auth_certificate = 2;
-  repeated bytes intermediate_certificate = 3;
-  optional SignatureAlgorithm signature_algorithm = 4
-      [default = RSASSA_PKCS1v15];
 }
 
 message AuthError {
   enum ErrorType {
     INTERNAL_ERROR = 0;
     NO_TLS = 1;  // The underlying connection is not TLS
-    SIGNATURE_ALGORITHM_UNAVAILABLE = 2;
   }
   required ErrorType error_type = 1;
 }