Add UMA stats for Chromoting connection details.

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 329decea3d212eefa74c3b3093d4bd65f85df4c4..4391c2ea1b3deb31bb165fa2f8fb3cf097e686d7 100644
--- a/remoting/webapp/base/js/client_session.js
+++ b/remoting/webapp/base/js/client_session.js
@@ -581,6 +581,8 @@ remoting.ClientSession.prototype.notifyStateChanges_ =
   var error;
   switch (this.state_) {
     case remoting.ClientSession.State.CONNECTED:
+      chrome.metricsPrivate.recordUserAction(

[kelvinp, 2015/08/20 23:21:23]

I think this will break our unit tests, as chrome.metricsPrivate won't be
defined.  Please add the definition to chrome_mocks.js

Can we group the all the metrics related call into a separate function like
updateMetrics() and call it in setState_() after notifyStateChanges()?

[anandc, 2015/08/21 03:15:42]

I ran ./remoting/tools/run_webapp_unittests.py and all tests passed. Is there
any other tests I should run?

+          'Chromoting.Connections.Connected');
       console.log('Connection established.');
       var connectionInfo = new remoting.ConnectionInfo(
           this.host_, this.credentialsProvider_, this, this.plugin_);
@@ -588,12 +590,16 @@ remoting.ClientSession.prototype.notifyStateChanges_ =
       break;
 
     case remoting.ClientSession.State.CONNECTING:
+      chrome.metricsPrivate.recordUserAction(
+          'Chromoting.Connections.Connecting');
       remoting.identity.getEmail().then(function(/** string */ email) {
         console.log('Connecting as ' + email);
       });
       break;
 
     case remoting.ClientSession.State.AUTHENTICATED:
+      chrome.metricsPrivate.recordUserAction(
+          'Chromoting.Connections.Authenticated');
       console.log('Connection authenticated.');
       break;
 
@@ -602,6 +608,7 @@ remoting.ClientSession.prototype.notifyStateChanges_ =
       break;
 
     case remoting.ClientSession.State.CLOSED:
+      chrome.metricsPrivate.recordUserAction('Chromoting.Connections.Closed');
       console.log('Connection closed.');
       this.listener_.onDisconnected(remoting.Error.none());
       break;
@@ -610,6 +617,7 @@ remoting.ClientSession.prototype.notifyStateChanges_ =
     case remoting.ClientSession.State.FAILED:
       error = this.getError();
       if (!error.isNone()) {
+        chrome.metricsPrivate.recordUserAction('Chromoting.Connections.Failed');
         console.error('Connection failed: ' + error.toString());
       }
       this.listener_.onConnectionFailed(error);
@@ -619,6 +627,7 @@ remoting.ClientSession.prototype.notifyStateChanges_ =
       error = this.getError();
       console.error('Connection dropped: ' + error.toString());
       this.listener_.onDisconnected(error);
+      chrome.metricsPrivate.recordUserAction('Chromoting.Connections.Dropped');
       break;
 
     default: