Revert of [cast_channel] Move cast_channel related files from //extensions to //components

components/cast_channel/proto/cast_channel.proto

-// Copyright 2014 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-syntax = "proto2";
-
-option optimize_for = LITE_RUNTIME;
-
-package cast_channel;
-
-message CastMessage {
-  // Always pass a version of the protocol for future compatibility
-  // requirements.
-  enum ProtocolVersion { CASTV2_1_0 = 0; }
-  required ProtocolVersion protocol_version = 1;
-
-  // source and destination ids identify the origin and destination of the
-  // message.  They are used to route messages between endpoints that share a
-  // device-to-device channel.
-  //
-  // For messages between applications:
-  //   - The sender application id is a unique identifier generated on behalf of
-  //     the sender application.
-  //   - The receiver id is always the the session id for the application.
-  //
-  // For messages to or from the sender or receiver platform, the special ids
-  // 'sender-0' and 'receiver-0' can be used.
-  //
-  // For messages intended for all endpoints using a given channel, the
-  // wildcard destination_id '*' can be used.
-  required string source_id = 2;
-  required string destination_id = 3;
-
-  // This is the core multiplexing key.  All messages are sent on a namespace
-  // and endpoints sharing a channel listen on one or more namespaces.  The
-  // namespace defines the protocol and semantics of the message.
-  required string namespace = 4;
-
-  // Encoding and payload info follows.
-
-  // What type of data do we have in this message.
-  enum PayloadType {
-    STRING = 0;
-    BINARY = 1;
-  }
-  required PayloadType payload_type = 5;
-
-  // Depending on payload_type, exactly one of the following optional fields
-  // will always be set.
-  optional string payload_utf8 = 6;
-  optional bytes payload_binary = 7;
-}
-
-enum SignatureAlgorithm {
-  UNSPECIFIED = 0;
-  RSASSA_PKCS1v15 = 1;
-  RSASSA_PSS = 2;
-}
-
-enum HashAlgorithm {
-  SHA1 = 0;
-  SHA256 = 1;
-}
-
-// Messages for authentication protocol between a sender and a receiver.
-message AuthChallenge {
-  optional SignatureAlgorithm signature_algorithm = 1
-      [default = RSASSA_PKCS1v15];
-  optional bytes sender_nonce = 2;
-  optional HashAlgorithm hash_algorithm = 3 [default = SHA1];
-}
-
-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];
-  optional bytes sender_nonce = 5;
-  optional HashAlgorithm hash_algorithm = 6 [default = SHA1];
-  optional bytes crl = 7;
-}
-
-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;
-}
-
-message DeviceAuthMessage {
-  // Request fields
-  optional AuthChallenge challenge = 1;
-  // Response fields
-  optional AuthResponse response = 2;
-  optional AuthError error = 3;
-}