Adding the message writing class used for remote_security_key STDOUT communication.

remoting/host/security_key/security_key_message.cc

 // Copyright 2016 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.
 
 #include "remoting/host/security_key/security_key_message.h"
 
 #include "base/logging.h"
 
 namespace {
 
 // Limit remote security key messages to 256KB.
 const uint32_t kMaxSecurityKeyMessageByteCount = 256 * 1024;
 
-const int kRemoteSecurityKeyMessageControlCodeByteCount = 1;
-
 }  // namespace
 
 namespace remoting {
 
+const int SecurityKeyMessage::kHeaderSizeBytes = 4;
+
+const int SecurityKeyMessage::kMessageTypeSizeBytes = 1;
+
 SecurityKeyMessage::SecurityKeyMessage() {}
 
 SecurityKeyMessage::~SecurityKeyMessage() {}
 
 bool SecurityKeyMessage::IsValidMessageSize(uint32_t message_size) {
   return message_size > 0 && message_size <= kMaxSecurityKeyMessageByteCount;
 }
 
 RemoteSecurityKeyMessageType SecurityKeyMessage::MessageTypeFromValue(
     int value) {
@@ skipping 38 matching lines @@
     return false;
   }
 
   // The first char of the message is the message type.
   type_ = MessageTypeFromValue(message_data[0]);
   if (type_ == RemoteSecurityKeyMessageType::INVALID) {
     return false;
   }
 
   payload_.clear();
-  if (message_data.size() > kRemoteSecurityKeyMessageControlCodeByteCount) {
+  if (message_data.size() > kMessageTypeSizeBytes) {
     payload_ = message_data.substr(1);
   }
 
   return true;
 }
 
 }  // namespace remoting