Credential Manager API: Enable forward declaration for CredentialType enum

components/password_manager/content/common/credential_manager_messages.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.
 
 // Message definition file, included multiple times, hence no include guard.
 
 #include <string>
 #include <vector>
 
 #include "base/strings/string16.h"
 #include "components/password_manager/content/common/credential_manager_types.h"
 #include "content/public/common/common_param_traits.h"
 #include "content/public/common/common_param_traits_macros.h"
 #include "ipc/ipc_message_macros.h"
 #include "ipc/ipc_message_utils.h"
 #include "third_party/WebKit/public/platform/WebCredentialManagerError.h"
 #include "url/gurl.h"
 
 #define IPC_MESSAGE_START CredentialManagerMsgStart
 
-IPC_ENUM_TRAITS_MAX_VALUE(password_manager::CredentialType,
-                          password_manager::CREDENTIAL_TYPE_LAST)
+IPC_ENUM_TRAITS_MAX_VALUE(
+    password_manager::CredentialType,
+    password_manager::CredentialType::CREDENTIAL_TYPE_LAST)
 
 IPC_ENUM_TRAITS_MAX_VALUE(blink::WebCredentialManagerError::ErrorType,
                           blink::WebCredentialManagerError::ErrorTypeLast)
 
 IPC_STRUCT_TRAITS_BEGIN(password_manager::CredentialInfo)
   IPC_STRUCT_TRAITS_MEMBER(type)
   IPC_STRUCT_TRAITS_MEMBER(id)
   IPC_STRUCT_TRAITS_MEMBER(name)
   IPC_STRUCT_TRAITS_MEMBER(avatar)
   IPC_STRUCT_TRAITS_MEMBER(password)
@@ skipping 58 matching lines @@
 IPC_MESSAGE_ROUTED2(CredentialManagerMsg_SendCredential,
                     int /* request_id */,
                     password_manager::CredentialInfo /* credential */)
 
 // Reject the credential request in response to a
 // CredentialManagerHostMsg_RequestCredential message.
 IPC_MESSAGE_ROUTED2(
     CredentialManagerMsg_RejectCredentialRequest,
     int /* request_id */,
     blink::WebCredentialManagerError::ErrorType /* rejection_reason */)