[cast_channel] Clean up CastSocketImpl ctor parameters

extensions/browser/api/cast_channel/cast_channel_enum_util.h

 // Copyright 2017 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.
 
 #ifndef EXTENSIONS_BROWSER_API_CAST_CHANNEL_CAST_CHANNEL_TYPE_UTIL_H_
 #define EXTENSIONS_BROWSER_API_CAST_CHANNEL_CAST_CHANNEL_TYPE_UTIL_H_
 
 #include "components/cast_channel/cast_channel_enum.h"
 #include "extensions/common/api/cast_channel.h"
 
 namespace extensions {
 namespace api {
 namespace cast_channel {
 
 api::cast_channel::ReadyState ToReadyState(
     ::cast_channel::ReadyState ready_state);
 api::cast_channel::ChannelError ToChannelError(
     ::cast_channel::ChannelError channel_error);
-api::cast_channel::ChannelAuthType ToChannelAuthType(
-    ::cast_channel::ChannelAuthType channel_auth);
-::cast_channel::ChannelAuthType ToChannelAuthTypeInternal(
-    api::cast_channel::ChannelAuthType channel_auth);
 
 }  // namespace cast_channel
 }  // namespace api
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_API_CAST_CHANNEL_CAST_CHANNEL_TYPE_UTIL_H_