[Chromoting] Plugin message in JingleMessage

remoting/protocol/jingle_messages.h

 // Copyright (c) 2012 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_JINGLE_MESSAGES_H_
 #define REMOTING_PROTOCOL_JINGLE_MESSAGES_H_
 
 #include <list>
 #include <memory>
 #include <string>
@@ skipping 83 matching lines @@
 
   std::string initiator;
 
   std::unique_ptr<ContentDescription> description;
 
   std::unique_ptr<buzz::XmlElement> transport_info;
 
   // Content of session-info messages.
   std::unique_ptr<buzz::XmlElement> info;
 
+  // Content of plugin message. The node is read or written by all plugins, and

[Sergey Ulanov, 2016/12/12 23:00:03]

There can be more than one plugin, so I think this should be a vector.

[Hzj_jie, 2016/12/13 00:20:51]

Then we will need extra logic to decide which piece of data should be sent to a
certain plugin in JingleSession, which indeed can be placed in plugins
themselves. I.e. A plugin get entire plugin data, and decide which subnode it
should read from or write to.

[Sergey Ulanov, 2016/12/14 01:31:50]

I don't think it would increase complexity much. The dispatching code could look
as follows:
  for (auto& msg : plugin_messages) {
    for (auto& plugin : plugins_) { 
      if (plugin->HandleMessage(msg)) 
        break;
    }
  }

but feel free to keep the current approach (see the comment below).
I see. Then I think <plugin> is not the best name, as it stores information for
multiple plugins. <plugins> would be better, but still not very clear. Maybe
call it <attachements>?

[Hzj_jie, 2016/12/14 20:03:48]

Yes, "attachments" is definitely good. Updated.

+  // ActionType independent.
+  std::unique_ptr<buzz::XmlElement> plugin_message;
+
   // Value from the <reason> tag if it is present in the
   // message. Useful mainly for session-terminate messages, but Jingle
   // spec allows it in any message.
   Reason reason = UNKNOWN_REASON;
 
   // Value from the <google:remoting:error-code> tag if it is present in the
   // message. Useful mainly for session-terminate messages. If it's UNKNOWN,
   // or reason is UNKNOWN_REASON, this field will be ignored in the xml output.
   ErrorCode error_code = UNKNOWN_ERROR;
 };
@@ skipping 57 matching lines @@
   std::unique_ptr<buzz::XmlElement> ToXml() const;
 
   std::list<IceCredentials> ice_credentials;
   std::list<NamedCandidate> candidates;
 };
 
 }  // protocol
 }  // remoting
 
 #endif  // REMOTING_PROTOCOL_JINGLE_MESSAGES_H_