Report the Auth method for me2me connections.

remoting/webapp/base/js/credentials_provider.js

 // Copyright 2015 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.
 
 'use strict';
 
 var remoting = remoting || {};
 
 /** @typedef {{clientId: string, sharedSecret: string}} */
 remoting.PairingInfo;
@@ skipping 32 matching lines @@
  */
 remoting.CredentialsProvider = function(args) {
   /** @private */
   this.fetchPin_ = (args.accessCode) ? this.getAccessCode_ : args.fetchPin;
   /** @private */
   this.pairingInfo_ = args.pairingInfo;
   /** @private */
   this.accessCode_ = args.accessCode;
   /** @private */
   this.fetchThirdPartyToken_ = args.fetchThirdPartyToken;
+
+  /** @private {?remoting.ChromotingEvent.AuthMethod} */
+  this.authMethod_ = null;
 };
 
 /** @returns {void}  */
 remoting.CredentialsProvider.prototype.getAccessCode_ = function(
   /** boolean */ supportsPairing, /** Function */ callback) {
+  this.authMethod_ = remoting.ChromotingEvent.AuthMethod.ACCESS_CODE;
   callback(this.accessCode_);
 };
 
 /** @returns {remoting.PairingInfo}  */
 remoting.CredentialsProvider.prototype.getPairingInfo = function() {
+  if (this.pairingInfo_) {
+    this.authMethod_ = remoting.ChromotingEvent.AuthMethod.PINLESS;
+  }
   return this.pairingInfo_ || { clientId: '', sharedSecret: ''};
 };
 
 /**
  * @param {boolean} pairingSupported Whether pairing is supported by the host.
  * @returns {Promise<string>}
  */
 remoting.CredentialsProvider.prototype.getPIN = function(pairingSupported) {
   var that = this;
   if (!this.fetchPin_) {
     Promise.resolve('');
   }
+
+  this.authMethod_ = remoting.ChromotingEvent.AuthMethod.PIN;
   return new Promise(function(/** function(string) */ resolve) {
     that.fetchPin_(pairingSupported, resolve);
   });
 };
 
 /**
  * @param {string} tokenUrl Token-issue URL received from the host.
  * @param {string} hostPublicKey Host public key (DER and Base64 encoded).
  * @param {string} scope OAuth scope to request the token for.
  *
  * @returns {Promise<remoting.ThirdPartyToken>}
  */
 remoting.CredentialsProvider.prototype.getThirdPartyToken = function(
     tokenUrl, hostPublicKey, scope) {
   var that = this;
   if (!this.fetchThirdPartyToken_) {
     Promise.resolve({token: '', secret: ''});
   }
+
+  this.authMethod_ = remoting.ChromotingEvent.AuthMethod.THIRD_PARTY;
   return new Promise(function(/** Function */ resolve) {
     var onTokenFetched = function(/** string */ token, /** string */ secret) {
       resolve({token: token, secret: secret});
     };
     that.fetchThirdPartyToken_(tokenUrl, hostPublicKey, scope, onTokenFetched);
   });
 };
+
+/** @return {?remoting.ChromotingEvent.AuthMethod} */
+remoting.CredentialsProvider.prototype.getAuthMethod = function() {
+  return this.authMethod_;
+};