[Chromoting] Use google:remoting namespace to export remoting specific error codes

remoting/protocol/jingle_messages.cc

Index: remoting/protocol/jingle_messages.cc
diff --git a/remoting/protocol/jingle_messages.cc b/remoting/protocol/jingle_messages.cc
index 3113873b01280f3e310b165bb005364e44fbaa38..ddc71b8e27d889c0f96c713f80240f8b90e275b6 100644
--- a/remoting/protocol/jingle_messages.cc
+++ b/remoting/protocol/jingle_messages.cc
@@ -49,7 +49,6 @@ const NameMapElement<JingleMessage::ActionType> kActionTypes[] = {
 const NameMapElement<JingleMessage::Reason> kReasons[] = {
   { JingleMessage::SUCCESS, "success" },
   { JingleMessage::DECLINE, "decline" },
-  { JingleMessage::SECURITY_ERROR, "security-error" },
   { JingleMessage::CANCEL, "cancel" },
   { JingleMessage::EXPIRED, "expired" },
   { JingleMessage::GENERAL_ERROR, "general-error" },
@@ -343,6 +342,16 @@ bool JingleMessage::ParseXml(const buzz::XmlElement* stanza,
     }
   }
 
+  const XmlElement* error_code_tag =
+      jingle_tag->FirstNamed(QName(kChromotingXmlNamespace, "error-code"));
+  if (error_code_tag && error_code_tag->FirstElement()) {
+    if (!NameToValue(kErrorCodes,
+                     error_code_tag->FirstElement()->Name().LocalPart(),
+                     &error_code)) {
+      error_code = UNKNOWN_ERROR;

[Sergey Ulanov, 2016/06/02 09:26:03]

log a warning that the error code wasn't recognized.

[Hzj_jie, 2016/06/02 22:00:18]

Done.

+    }
+  }
+
   if (action == SESSION_TERMINATE)
     return true;
 
@@ -360,7 +369,7 @@ bool JingleMessage::ParseXml(const buzz::XmlElement* stanza,
   }
 
   const XmlElement* webrtc_transport_tag = content_tag->FirstNamed(
-      QName("google:remoting:webrtc", "transport"));
+      QName(kWebrtcTransportNamespace, "transport"));
   if (webrtc_transport_tag) {
     transport_info.reset(new buzz::XmlElement(*webrtc_transport_tag));
   }
@@ -424,12 +433,23 @@ std::unique_ptr<buzz::XmlElement> JingleMessage::ToXml() const {
   if (reason != UNKNOWN_REASON) {
     XmlElement* reason_tag = new XmlElement(QName(kJingleNamespace, "reason"));
     jingle_tag->AddElement(reason_tag);
-    const char* reason_string =
-        ValueToName(kReasons, reason);
+    const char* reason_string = ValueToName(kReasons, reason);
     if (!reason_string)
       LOG(FATAL) << "Invalid reason: " << reason;
     reason_tag->AddElement(new XmlElement(
         QName(kJingleNamespace, reason_string)));
+
+    if (error_code != UNKNOWN_ERROR) {
+      XmlElement* error_code_tag =
+          new XmlElement(QName(kChromotingXmlNamespace, "error-code"));
+      jingle_tag->AddElement(error_code_tag);
+      const char* error_code_string = ValueToName(kErrorCodes, error_code);
+      if (!error_code_string) {

[Sergey Ulanov, 2016/06/02 09:26:04]

replace with DCHECK(error_code_string)

[Hzj_jie, 2016/06/02 22:00:18]

Done.

+        LOG(FATAL) << "Invalid error code: " << static_cast<int>(error_code);
+      }
+      error_code_tag->AddElement(new XmlElement(

[Sergey Ulanov, 2016/06/02 09:26:03]

I don't think we want to add the error as element. Insert it as text.
I.e. it should be <error-code>PEER_IS_OFFLINE</error-code> instead of
<error-code><PEER_IS_OFFLINE/></error-code>

[Hzj_jie, 2016/06/02 22:00:18]

I used to implement as a text, but I found it's not a good idea. Do we treat
<error-code> PEER_IS_OFFLINE</error-code> and
<error-code>
    PEER_IS_OFFLINE
</error-code>
the same as <error-code>PEER_IS_OFFLINE</error-code>.
I did not see libjingle implements whiteSpace=collapsed scenario, and there is
also no whiteSpace=collapsed defined in our Xml output, which makes us need to
do trim and collapse ourselves.

And current solution is also consistent with other jingle errors.

[Sergey Ulanov, 2016/06/03 08:43:22]

I don't see how that can be a problem. When we generate
<error-code>FOO</error-code> we should get <error-code>FOO</error-code> on the
other end. If whitespace gets inserted there somehow it's a bug. There are other
places where we depend on whitespace not being inserted in random places. Beside
that it's easy to trim the whitepsace if we necessary. And if we really wanted
to be consistent with the Jingle's reason codes, then it would need to be
<rem:foo-error> instead of <rem:error-code>FOO_ERROR</rem:error-code>

[Hzj_jie, 2016/06/03 21:46:33]

Done.

+          QName(kChromotingXmlNamespace, error_code_string)));
+    }
   }
 
   if (action != SESSION_TERMINATE) {