extensions: Cleanup class/struct fwd declarations

extensions/browser/api/cast_channel/cast_auth_util.h

 // 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.
 
 #ifndef EXTENSIONS_BROWSER_API_CAST_CHANNEL_CAST_AUTH_UTIL_H_
 #define EXTENSIONS_BROWSER_API_CAST_CHANNEL_CAST_AUTH_UTIL_H_
 
 #include <string>
 
 #include "base/memory/ref_counted.h"
 #include "base/time/time.h"
 
 namespace cast_certificate {
 enum class CRLPolicy;
 }
 
 namespace net {
 class X509Certificate;
 class TrustStore;
 }  // namespace net
 
 namespace extensions {
 namespace api {
 namespace cast_channel {
 
 class AuthResponse;
 class CastMessage;
-class DeviceAuthMessage;
 
 struct AuthResult {
  public:
   enum ErrorType {
     ERROR_NONE,
     ERROR_PEER_CERT_EMPTY,
     ERROR_WRONG_PAYLOAD_TYPE,
     ERROR_NO_PAYLOAD,
     ERROR_PAYLOAD_PARSING_FAILED,
     ERROR_MESSAGE_ERROR,
@@ skipping 51 matching lines @@
     const cast_certificate::CRLPolicy& crl_policy,
     net::TrustStore* cast_trust_store,
     net::TrustStore* crl_trust_store,
     const base::Time& verification_time);
 
 }  // namespace cast_channel
 }  // namespace api
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_API_CAST_CHANNEL_CAST_AUTH_UTIL_H_