[Chromoting] Use HostExperimentSessionPlugin in host

remoting/host/host_session_options.h

 // 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.
 
-#ifndef REMOTING_PROTOCOL_HOST_SESSION_OPTIONS_H_
-#define REMOTING_PROTOCOL_HOST_SESSION_OPTIONS_H_
+#ifndef REMOTING_HOST_HOST_SESSION_OPTIONS_H_
+#define REMOTING_HOST_HOST_SESSION_OPTIONS_H_
 
 #include <map>
 #include <string>
 
 #include "base/macros.h"
 #include "base/optional.h"
 
 namespace remoting {
-namespace protocol {
 
 // Session based host options sending from client. This class parses and stores
 // session configuration from client side to control the behavior of other host
 // components.
 class HostSessionOptions final {
  public:
   HostSessionOptions();
   ~HostSessionOptions();
 
+  HostSessionOptions(const std::string& parameter);
+
   // Appends one key-value pair into current instance.
   void Append(const std::string& key, const std::string& value);
 
   // Retrieves the value of |key|. Returns a true Optional if |key| has been
   // found, value of the Optional wil be set to corresponding value.
   base::Optional<std::string> Get(const std::string& key) const;
 
   // Returns a string to represent current instance. Consumers can rebuild an
   // exactly same instance with Import() function.
   std::string Export() const;
 
   // Overwrite current instance with |parameter|, which is a string returned by
   // Export() function. So a parent process can send HostSessionOptions to a
   // child process.
   void Import(const std::string& parameter);
 
  private:
   std::map<std::string, std::string> options_;
 
   HostSessionOptions(HostSessionOptions&&) = delete;
   HostSessionOptions& operator=(HostSessionOptions&&) = delete;
   DISALLOW_COPY_AND_ASSIGN(HostSessionOptions);
 };
 
-}  // namespace protocol
 }  // namespace remoting
 
-#endif  // REMOTING_PROTOCOL_HOST_SESSION_OPTIONS_H_
+#endif  // REMOTING_HOST_HOST_SESSION_OPTIONS_H_