Use Chromium BUILD to approximate Blimp protocol version, and check it.

blimp/common/create_blimp_message.h

 // Copyright 2015 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 BLIMP_COMMON_CREATE_BLIMP_MESSAGE_H_
 #define BLIMP_COMMON_CREATE_BLIMP_MESSAGE_H_
 
 #include <stdint.h>
 
 #include <memory>
 #include <string>
 
 #include "blimp/common/blimp_common_export.h"
+#include "blimp/common/proto/protocol_control.pb.h"
 
 namespace blimp {
 
 class BlimpMessage;
 class BlobChannelMessage;
 class CompositorMessage;
 class EngineSettingsMessage;
 class ImeMessage;
 class InputMessage;
 class NavigationMessage;
 class RenderWidgetMessage;
 class SettingsMessage;
 class SizeMessage;
-class StartConnectionMessage;
 class TabControlMessage;
 
 // Suite of helper methods to simplify the repetitive task of creating
 // new BlimpMessages, initializing them, and extracting type-specific
 // inner messages.
 //
 //
 // Every specialization of CreateBlimpMessage returns an initialized
 // BlimpMessage object. In addition, a pointer to the type-specific inner
 // message is returned via the initial double-pointer parameter.
@@ skipping 32 matching lines @@
 BLIMP_COMMON_EXPORT std::unique_ptr<BlimpMessage> CreateBlimpMessage(
     BlobChannelMessage** blob_channel_message);
 
 BLIMP_COMMON_EXPORT std::unique_ptr<BlimpMessage> CreateStartConnectionMessage(
     const std::string& client_token,
     int protocol_version);
 
 BLIMP_COMMON_EXPORT std::unique_ptr<BlimpMessage> CreateCheckpointAckMessage(
     int64_t checkpoint_id);
 
+BLIMP_COMMON_EXPORT std::unique_ptr<BlimpMessage> CreateEndConnectionMessage(
+    EndConnectionMessage::Reason reason);
+
 }  // namespace blimp
 
 #endif  // BLIMP_COMMON_CREATE_BLIMP_MESSAGE_H_