Support LCS signaling address in the Host.

remoting/protocol/jingle_messages.h

Index: remoting/protocol/jingle_messages.h
diff --git a/remoting/protocol/jingle_messages.h b/remoting/protocol/jingle_messages.h
index e81d86237cca6cb624df75b76280721df78c646a..f4631de2f881a035b00fcea4e1def4231b541655 100644
--- a/remoting/protocol/jingle_messages.h
+++ b/remoting/protocol/jingle_messages.h
@@ -17,6 +17,56 @@ namespace protocol {
 
 class ContentDescription;
 
+// Represents an address of a Chromoting endpoint and its routing channel.
+struct Address {

[Sergey Ulanov, 2016/05/18 07:00:42]

I think this belongs to remoting/signaling. Potentially we could update
SignalStrategy interface to use this instead of jid for addressing. Maybe keep
it here for now, but add a TODO.
Also it should be called SignalingAddress. Address is a too generic name. 

[kelvinp, 2016/05/18 23:43:29]

Done.

+  enum Channel {

[Sergey Ulanov, 2016/05/18 07:00:42]

enum class please, here and for enums below

[kelvinp, 2016/05/18 23:43:29]

Done.

+    LCS,
+    XMPP
+  };
+
+  enum Role {

[Sergey Ulanov, 2016/05/18 07:00:42]

this enum is confusing. I suggest removing it and replace ParseXml and ToXml
with GetTo(), GetFrom(), SetTo() and SetFrom().

[kelvinp, 2016/05/18 23:43:28]

Removed.

+    FROM,
+    TO
+  };
+
+  // Represents the XML attrbute names for the various address fields in the
+  // iq stanza.
+  enum Attribute  {
+    JID,
+    CHANNEL,
+    ENDPOINT_ID
+  };
+
+  Address();
+  explicit Address(const std::string& jid);
+
+  // Represents the |to| or |from| field in an IQ stanza.
+  std::string jid;
+
+  // Represents the identifier of an endpoint. In XMPP, this is the JID.  In

[Sergey Ulanov, 2016/05/18 07:00:42]

It feels wrong that we duplicate JID for XMPP. Why not store these values the
same values the way they are present in XML. I.e. set endpoint_id only when
channel = LCS and keep it empty otherwise.

[kelvinp, 2016/05/18 23:43:29]

Done.

+  // LCS, this is the LCS address encoded in a JID like format
+  // e.g.user@gmail.com/ResourceID. However,the resource ID can contain invalid
+  // JID characters (e.g. =), since LCS addresses are base64 encoded).
+  std::string endpoint_id;
+  Channel channel;
+
+  // Parses |stanza|.  Caller keeps ownership of |stanza|.  If the parsing
+  // fails, false is returned and |error| is set the error message for
+  // debugging.  Returns true for empty address fields.
+  bool ParseXml(const buzz::XmlElement* stanza, Role role, std::string* error);

[Sergey Ulanov, 2016/05/18 07:00:41]

I don't think these two functions need to be class members. You can replace them
with static helpers in jingle_messages.cc

[kelvinp, 2016/05/18 23:43:29]

Removed.

+
+  // Populates the corresponding address fields in |stanza| for |role|.  Caller
+  // keeps ownership of |stanza|.
+  void toXml(buzz::XmlElement* iqElement, Role role) const;

[Sergey Ulanov, 2016/05/18 07:00:42]

I don't think toXml() is a good name as it doesn't return XML.
I suggest replacing with SetToField() and SetFromField(), without the role
parameter.

[kelvinp, 2016/05/18 23:43:29]

Removed.

+
+  bool empty() const;

[Sergey Ulanov, 2016/05/18 07:00:41]

is_empty().
inline this method?

[kelvinp, 2016/05/18 23:43:29]

Done.

+
+  static buzz::QName GetQName(Role role, Attribute attr);
+
+  bool operator==(const Address& other);
+  bool operator!=(const Address& other);
+};
+
 struct JingleMessage {
   enum ActionType {
     UNKNOWN_ACTION,
@@ -40,7 +90,7 @@ struct JingleMessage {
 
 
   JingleMessage();
-  JingleMessage(const std::string& to_value,
+  JingleMessage(const Address& to,
                 ActionType action_value,
                 const std::string& sid_value);
   ~JingleMessage();
@@ -55,8 +105,8 @@ struct JingleMessage {
 
   std::unique_ptr<buzz::XmlElement> ToXml() const;
 
-  std::string from;
-  std::string to;
+  Address from;
+  Address to;
   ActionType action = UNKNOWN_ACTION;
   std::string sid;