[Chromoting] Add SessionPlugin in JingleSession

remoting/protocol/jingle_messages.cc

 // 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.
 
 #include "remoting/protocol/jingle_messages.h"
 
 #include "base/logging.h"
 #include "base/strings/string_number_conversions.h"
 #include "remoting/base/constants.h"
 #include "remoting/protocol/content_description.h"
 #include "remoting/protocol/name_value_map.h"
+#include "remoting/protocol/session_plugin.h"
 #include "remoting/signaling/jid_util.h"
 #include "remoting/signaling/remoting_bot.h"
 #include "third_party/webrtc/libjingle/xmllite/xmlelement.h"
 
 using buzz::QName;
 using buzz::XmlElement;
 
 namespace remoting {
 namespace protocol {
 
@@ skipping 482 matching lines @@
       content_tag->AddElement(new XmlElement(*transport_info));
     } else if (description && description->config()->webrtc_supported()) {
       content_tag->AddElement(
           new XmlElement(QName(kWebrtcTransportNamespace, "transport")));
     }
   }
 
   return root;
 }
 
+void JingleMessage::AttachAttachment(std::unique_ptr<XmlElement> attachment) {
+  if (!attachment) {

[Sergey Ulanov, 2016/12/21 01:38:34]

I don't think we want to allow attachment to be null here.

[Hzj_jie, 2016/12/22 00:27:10]

Done.

The null check needs to be placed either here or in JingleSession. IMO, here is
better. Logically speaking it's a little bit weird, what's the point to attach
an empty attachment. But it can save an std::move in JingleSession.

+    return;
+  }
+  if (!attachments) {
+    attachments.reset(new XmlElement(
+        QName(kChromotingXmlNamespace, "attachments")));
+  }
+  attachments->AddElement(attachment.release());
+}
+
 JingleMessageReply::JingleMessageReply()
     : type(REPLY_RESULT),
       error_type(NONE) {
 }
 
 JingleMessageReply::JingleMessageReply(ErrorType error)
     : type(error != NONE ? REPLY_ERROR : REPLY_RESULT),
       error_type(error) {
 }
 
@@ skipping 151 matching lines @@
     result->AddElement(FormatIceCredentials(credentials));
   }
   for (const NamedCandidate& candidate : candidates) {
     result->AddElement(FormatIceCandidate(candidate));
   }
   return result;
 }
 
 }  // namespace protocol
 }  // namespace remoting