Include time elapsed since start of a remoting session in each log entry.

remoting/webapp/crd/js/log_to_server.js

 // Copyright (c) 2012 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.
 
 /**
  * @fileoverview
  * Module for sending log entries to the server.
  */
 
 'use strict';
 
 /** @suppress {duplicate} */
 var remoting = remoting || {};
 
 /**
  * @param {remoting.SignalStrategy} signalStrategy Signal strategy.
  * @param {remoting.DesktopConnectedView.Mode} mode The mode of this connection.
  * @constructor
  */
 remoting.LogToServer = function(signalStrategy, mode) {
   /** @private */
   this.statsAccumulator_ = new remoting.StatsAccumulator();
   /** @private */
   this.sessionId_ = '';
   /** @private */
   this.sessionIdGenerationTime_ = 0;
   /** @private */
   this.sessionStartTime_ = 0;

[Jamie, 2015/02/28 00:35:37]

You need to initialize this to the current time. Also, please make sure that you
don't see any significant time gap between the ctor and where the start time was
previously being initialized. If it's more than a few milliseconds, then we'll
see a discontinuity in our stats before and after landing this change.

[anandc, 2015/02/28 01:20:27]

Done.
I tested the additional time doing it here adds to subsequent elapsed time
calculations, and noticed that we add about 200ms. This is just the 1st time I
connected to a host. The next time, we added about 120-150ms.
That seems a little high but should be acceptable.

   /** @private */
   this.signalStrategy_ = signalStrategy;
   /** @private */
   this.mode_ = mode;
   /** @type {string} @private */
   this.connectionType_ = '';
 
   this.setSessionId_();
   signalStrategy.sendConnectionSetupResults(this);
 };
@@ skipping 32 matching lines @@
       state, connectionError, this.mode_);
   entry.addHostFields();
   entry.addChromeVersionField();
   entry.addWebappVersionField();
   entry.addSessionIdField(this.sessionId_);
   // Maybe clear the session start time, and log the session duration.
   if (remoting.LogToServer.shouldAddDuration_(state) &&
       (this.sessionStartTime_ != 0)) {
     entry.addSessionDurationField(
         (new Date().getTime() - this.sessionStartTime_) / 1000.0);
-    if (remoting.LogToServer.isEndOfSession_(state)) {
-      this.sessionStartTime_ = 0;
-    }
   }
+
   this.log_(entry);
   // Don't accumulate connection statistics across state changes.
   this.logAccumulatedStatistics_();
   this.statsAccumulator_.empty();
   // Maybe clear the session ID.
   if (remoting.LogToServer.isEndOfSession_(state)) {
     this.clearSessionId_();
   }
+
 };
 
 /**
  * Set the connection type (direct, stun relay).
  *
  * @param {string} connectionType
  */
 remoting.LogToServer.prototype.setConnectionType = function(connectionType) {
   this.connectionType_ = connectionType;
 };
 
 /**
  * @param {remoting.SignalStrategy.Type} strategyType
  * @param {remoting.FallbackSignalStrategy.Progress} progress
- * @param {number} elapsedTimeInMs
  */
 remoting.LogToServer.prototype.logSignalStrategyProgress =
-    function(strategyType, progress, elapsedTimeInMs) {
+    function(strategyType, progress) {
   this.maybeExpireSessionId_();
   var entry = remoting.ServerLogEntry.makeSignalStrategyProgress(
-      this.sessionId_, strategyType, progress, elapsedTimeInMs);
+      this.sessionId_, strategyType, progress);
   this.log_(entry);
 };
 
 /**
  * Whether a session state is one of the states that occurs at the start of
  * a session.
  *
  * @private
  * @param {remoting.ClientSession.State} state
  * @return {boolean}
@@ skipping 72 matching lines @@
   this.statsAccumulator_.empty();
 };
 
 /**
  * Sends a log entry to the server.
  *
  * @private
  * @param {remoting.ServerLogEntry} entry
  */
 remoting.LogToServer.prototype.log_ = function(entry) {
+  // Log the time taken to get to this point from the time this session started.
+  var elapsedTimeInMs = new Date().getTime() - this.sessionStartTime_;
+  entry.addElapsedTimeMs(elapsedTimeInMs);
+
   // Send the stanza to the debug log.
   console.log('Enqueueing log entry:');
   entry.toDebugLog(1);
 
   var stanza = '<cli:iq to="' + remoting.settings.DIRECTORY_BOT_JID + '" ' +
                        'type="set" xmlns:cli="jabber:client">' +
                  '<gr:log xmlns:gr="google:remoting">' +
                    entry.toStanza() +
                  '</gr:log>' +
                '</cli:iq>';
@@ skipping 54 matching lines @@
 remoting.LogToServer.generateSessionId_ = function() {
   var idArray = [];
   for (var i = 0; i < remoting.LogToServer.SESSION_ID_LEN_; i++) {
     var index =
         Math.random() * remoting.LogToServer.SESSION_ID_ALPHABET_.length;
     idArray.push(
         remoting.LogToServer.SESSION_ID_ALPHABET_.slice(index, index + 1));
   }
   return idArray.join('');
 };