Report the Auth method for me2me connections.

remoting/webapp/base/js/client_session.js

Index: remoting/webapp/base/js/client_session.js
diff --git a/remoting/webapp/base/js/client_session.js b/remoting/webapp/base/js/client_session.js
index ac74e948708b8fafb0dede7b2edd3b0a97cb7ce9..ebb0bb49d822e0af978c7ddbde4122c019efbfb3 100644
--- a/remoting/webapp/base/js/client_session.js
+++ b/remoting/webapp/base/js/client_session.js
@@ -550,6 +550,7 @@ remoting.ClientSession.prototype.setState_ = function(newState) {
     this.connectedDisposables_ = null;
   }
 
+  this.logAuthMethod_();
   this.notifyStateChanges_(oldState, this.state_);
   // Record state count in an UMA enumerated histogram.
   recordState(this.state_);
@@ -557,6 +558,19 @@ remoting.ClientSession.prototype.setState_ = function(newState) {
       this.state_, this.error_, this.xmppErrorCache_.getFirstError());
 };
 
+/** @private */
+remoting.ClientSession.prototype.logAuthMethod_ = function() {
+  // The AuthMethod is undefined before the AUTHENTICATED stage for a
+  // successful connection or the FAILED stage for a failed connection.
+  if (this.state_ == remoting.ClientSession.State.AUTHENTICATED ||
+      this.state_ == remoting.ClientSession.State.FAILED) {

[Jamie, 2015/10/09 01:17:21]

Rather than relying on this, couldn't you have getAuthMethod return null? Feel
free to ignore if this code will change substantially when you refactor the
plugin code to notify the auth method explicitly.

[kelvinp, 2015/10/09 18:00:34]

The scenario that I am trying to cover is the following:

If you have a pairing info in local storage (but pairing is disabled on the host
side), we will always read the pairing info from the credentials provider the
session.  Due to the limitations that you have pointed out before, the session
will be first reported with pairing as the auth method.  However, upon
authentication, it fails and the host will ask for a PIN.  As a result, the
CONNECTING events of the session will be reported using pairing whereas
AUTHENTICATED will be reported using PIN.

+    var authMethod = this.credentialsProvider_.getAuthMethod();
+    if (authMethod != null) {
+      this.logger_.setAuthMethod(authMethod);
+    }
+  }
+};
+
 /**
  * Records a Chromoting Connection State, stored in an UMA enumerated histogram.
  * @param {remoting.ClientSession.State} state State identifier.