Bug 808002: add missing consts lost in main landing for unreliable data channels r=anant

dom/media/PeerConnection.js

@@ -450,11 +450,11 @@ PeerConnection.prototype = {
     // Must determine the type where we still know if entries are undefined.
     let type;
     if (dict.maxRetransmitTime != undefined) {
-      type = Ci.IPeerConnection.DATACHANNEL_PARTIAL_RELIABLE_TIMED;
+      type = Ci.IPeerConnection.kDataChannelPartialReliableTimed;
     } else if (dict.maxRetransmitNum != undefined) {
-      type = Ci.IPeerConnection.DATACHANNEL_PARTIAL_RELIABLE_REXMIT;
+      type = Ci.IPeerConnection.kDataChannelPartialReliableRexmit;
     } else {
-      type = Ci.IPeerConnection.DATACHANNEL_RELIABLE;
+      type = Ci.IPeerConnection.kDataChannelReliable;
     }
 
     // Synchronous since it doesn't block.

dom/media/bridge/IPeerConnection.idl

@@ -69,6 +69,11 @@ interface IPeerConnection : nsISupports
   const long kIceConnected = 3;
   const long kIceFailed = 4;
 
+  /* for 'type' in DataChannelInit dictionary */
+  const unsigned short kDataChannelReliable = 0;
+  const unsigned short kDataChannelPartialReliableRexmit = 1;
+  const unsigned short kDataChannelPartialReliableTimed = 2;
+
   /* Must be called first. Observer events will be dispatched on the thread provided */
   void initialize(in IPeerConnectionObserver observer, in nsIDOMWindow window,
                   [optional] in nsIThread thread);