Report the Auth method for me2me connections.

remoting/webapp/base/js/chromoting_event.js

Index: remoting/webapp/base/js/chromoting_event.js
diff --git a/remoting/webapp/base/js/chromoting_event.js b/remoting/webapp/base/js/chromoting_event.js
index 1e724cf9dcdf0f9fd500f6d1a754354f1aa4667e..c0c9e6723bacfde910537bffe94c02ccecc211a2 100644
--- a/remoting/webapp/base/js/chromoting_event.js
+++ b/remoting/webapp/base/js/chromoting_event.js
@@ -92,6 +92,9 @@ remoting.ChromotingEvent = function(type) {
   /** @type {number} */
   this.host_status_update_elapsed_time;
 
+  /** @type {remoting.ChromotingEvent.AuthMethod} */
+  this.auth_method;
+
   this.init_();
 };
 
@@ -284,3 +287,11 @@ remoting.ChromotingEvent.SignalStrategyProgress = {
   SUCCEEDED_LATE: 4,
   FAILED_LATE: 5
 };
+
+/** @enum {number} */
+remoting.ChromotingEvent.AuthMethod = {
+  PIN: 1,
+  ACCESS_CODE: 2,
+  PINLESS: 3,
+  THIRD_PARTY: 4,
+};