[Chromoting] Cleans up legacy code for XMPP-based logging.

This CL cleans up the legacy code from the XMPP based logging solution

Summary of changes:
1. Remove Log_to_Server.js, Server_Log_Entry.js, logger.js,
   buffered_signal_strategy.js
2. Use remoting.SessionLogger in host_screen.js

BUG=523423

Review URL: https://codereview.chromium.org/1399883005

Cr-Commit-Position: refs/heads/master@{#353634}

10 files changed, 114 insertions, 590 deletions

diff --git a/remoting/remoting_webapp_files.gypi b/remoting/remoting_webapp_files.gypi
index b18e540..9e3e1fb 100644
--- a/remoting/remoting_webapp_files.gypi
+++ b/remoting/remoting_webapp_files.gypi
@@ -214,10 +214,7 @@
     # Logging and stats JavaScript files.
     'remoting_webapp_shared_js_logging_files': [
       'webapp/base/js/chromoting_event.js',
-      'webapp/base/js/logger.js',
       'webapp/base/js/format_iq.js',
-      'webapp/base/js/log_to_server.js',
-      'webapp/base/js/server_log_entry.js',
       'webapp/base/js/session_logger.js',
       'webapp/base/js/stats_accumulator.js',
     ],
@@ -277,7 +274,6 @@
     # Files for controlling the local machine as a host.
     # Includes both it2me and me2me files.
     'remoting_webapp_js_host_control_files': [
-      'webapp/crd/js/buffered_signal_strategy.js',
       'webapp/crd/js/host_controller.js',
       'webapp/crd/js/host_daemon_facade.js',
       'webapp/crd/js/host_screen.js',
@@ -292,7 +288,6 @@
     # Files for controlling the local it2me host.
     # Included by public_session.html.
     'remoting_webapp_js_it2me_host_control_files': [
-      'webapp/crd/js/buffered_signal_strategy.js',
       'webapp/crd/js/host_screen.js',
       'webapp/crd/js/host_session.js',
       'webapp/crd/js/host_install_dialog.js',
diff --git a/remoting/webapp/base/js/client_session.js b/remoting/webapp/base/js/client_session.js
index ebb0bb4..7160f6f 100644
--- a/remoting/webapp/base/js/client_session.js
+++ b/remoting/webapp/base/js/client_session.js
@@ -24,7 +24,7 @@ var remoting = remoting || {};
 /**
  * @param {remoting.ClientPlugin} plugin
  * @param {remoting.SignalStrategy} signalStrategy Signal strategy.
- * @param {remoting.Logger} logger
+ * @param {remoting.SessionLogger} logger
  * @param {remoting.ClientSession.EventHandler} listener
  *
  * @constructor
@@ -57,7 +57,7 @@ remoting.ClientSession = function(
   /** @private */
   this.hasReceivedFrame_ = false;
 
-  /** @private {remoting.Logger} */
+  /** @private */
   this.logger_ = logger;
 
   /** @private */
@@ -135,6 +135,7 @@ remoting.ClientSession.EventHandler.prototype.onDisconnected =
 //
 // TODO(kelvinp): Merge this enum with remoting.ChromotingEvent.SessionState
 // once we have migrated away from XMPP-based logging (crbug.com/523423).
+//
 // NOTE: The enums here correspond to the Chromoting.Connections enumerated
 // histogram defined in src/tools/metrics/histograms/histograms.xml. UMA
 // histograms don't work well with negative values, so only non-negative values
@@ -331,7 +332,7 @@ remoting.ClientSession.prototype.getState = function() {
 };
 
 /**
- * @return {remoting.Logger}.
+ * @return {remoting.SessionLogger}.
  */
 remoting.ClientSession.prototype.getLogger = function() {
   return this.logger_;
diff --git a/remoting/webapp/base/js/fallback_signal_strategy.js b/remoting/webapp/base/js/fallback_signal_strategy.js
index 0596640..68623ae 100644
--- a/remoting/webapp/base/js/fallback_signal_strategy.js
+++ b/remoting/webapp/base/js/fallback_signal_strategy.js
@@ -73,7 +73,7 @@ remoting.FallbackSignalStrategy = function(primary,
   /** @private {number} */
   this.primaryConnectTimerId_ = 0;
 
-  /** @private {remoting.Logger} */
+  /** @private */
   this.logger_ = new remoting.SessionLogger(
       remoting.ChromotingEvent.Role.CLIENT,
       remoting.TelemetryEventWriter.Client.write
diff --git a/remoting/webapp/base/js/log_to_server.js b/remoting/webapp/base/js/log_to_server.js
deleted file mode 100644
index dc9162c..0000000
--- a/remoting/webapp/base/js/log_to_server.js
+++ /dev/null
@@ -1,319 +0,0 @@
-// 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 {boolean=} opt_isHost True if this instance should log role=host
- *     events rather than role=client.
- * @constructor
- * @implements {remoting.Logger}
- */
-remoting.LogToServer = function(signalStrategy, opt_isHost) {
-  /** @private */
-  this.statsAccumulator_ = new remoting.StatsAccumulator();
-  /** @private */
-  this.sessionId_ = '';
-  /** @private */
-  this.sessionIdGenerationTime_ = 0;
-  /** @private */
-  this.sessionStartTime_ = new Date().getTime();
-  /** @private */
-  this.signalStrategy_ = signalStrategy;
-  /** @private {string} */
-  this.connectionType_ = '';
-  /** @private */
-  this.authTotalTime_ = 0;
-  /** @private {string} */
-  this.hostVersion_ = '';
-  /** @private */
-  this.logEntryMode_ = remoting.ServerLogEntry.VALUE_MODE_UNKNOWN;
-  /** @private */
-  this.role_ = opt_isHost ? 'host' : 'client';
-
-  this.setSessionId();
-};
-
-// Constants used for generating a session ID.
-/** @private */
-remoting.LogToServer.SESSION_ID_ALPHABET_ =
-    'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890';
-/** @private */
-remoting.LogToServer.SESSION_ID_LEN_ = 20;
-
-/**
- * Logs a client session state change.
- *
- * @param {remoting.ClientSession.State} state
- * @param {!remoting.Error} connectionError
- * @param {?remoting.ChromotingEvent.XmppError} xmppError
- */
-remoting.LogToServer.prototype.logClientSessionStateChange =
-    function(state, connectionError, xmppError) {
-  this.maybeExpireSessionId_();
-  // Log the session state change.
-  var entry = remoting.ServerLogEntry.makeClientSessionStateChange(
-      state, connectionError, this.logEntryMode_, this.role_);
-  entry.addClientOSFields();
-  entry.addChromeVersionField();
-  entry.addWebappVersionField();
-  entry.addSessionIdField(this.sessionId_);
-  entry.addXmppError(xmppError);
-
-  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.ChromotingEvent.Mode} mode
- */
-remoting.LogToServer.prototype.setLogEntryMode = function(mode) {
-  switch (mode) {
-    case remoting.ChromotingEvent.Mode.IT2ME:
-      this.logEntryMode_ = remoting.ServerLogEntry.VALUE_MODE_IT2ME;
-      break;
-    case remoting.ChromotingEvent.Mode.ME2ME:
-      this.logEntryMode_ = remoting.ServerLogEntry.VALUE_MODE_ME2ME;
-      break;
-    case remoting.ChromotingEvent.Mode.LGAPP:
-      this.logEntryMode_ = remoting.ServerLogEntry.VALUE_MODE_APP_REMOTING;
-      break;
-    default:
-      this.logEntryMode_ = remoting.ServerLogEntry.VALUE_MODE_UNKNOWN;
-  }
-};
-
-/**
- * @param {remoting.SignalStrategy.Type} strategyType
- * @param {remoting.FallbackSignalStrategy.Progress} progress
- */
-remoting.LogToServer.prototype.logSignalStrategyProgress =
-    function(strategyType, progress) {
-  this.maybeExpireSessionId_();
-  var entry = remoting.ServerLogEntry.makeSignalStrategyProgress(
-      this.sessionId_, strategyType, progress);
-  this.log_(entry);
-};
-
-/**
- * @return {string} The current session id. This is random GUID, refreshed
- *     every 24hrs.
- */
-remoting.LogToServer.prototype.getSessionId = function() {
-  return this.sessionId_;
-};
-
-/**
- * Whether a session state is one of the states that occurs at the end of
- * a session.
- *
- * @private
- * @param {remoting.ClientSession.State} state
- * @return {boolean}
- */
-remoting.LogToServer.isEndOfSession_ = function(state) {
-  return ((state == remoting.ClientSession.State.CLOSED) ||
-      (state == remoting.ClientSession.State.FAILED) ||
-      (state == remoting.ClientSession.State.CONNECTION_DROPPED) ||
-      (state == remoting.ClientSession.State.CONNECTION_CANCELED));
-};
-
-
-/**
- * Logs connection statistics.
- * @param {Object<number>} stats The connection statistics
- */
-remoting.LogToServer.prototype.logStatistics = function(stats) {
-  this.maybeExpireSessionId_();
-  // Store the statistics.
-  this.statsAccumulator_.add(stats);
-  // Send statistics to the server if they've been accumulating for at least
-  // 60 seconds.
-  if (this.statsAccumulator_.getTimeSinceFirstValue() >=
-      remoting.Logger.CONNECTION_STATS_ACCUMULATE_TIME) {
-    this.logAccumulatedStatistics_();
-  }
-};
-
-/**
- * Moves connection statistics from the accumulator to the log server.
- *
- * If all the statistics are zero, then the accumulator is still emptied,
- * but the statistics are not sent to the log server.
- *
- * @private
- */
-remoting.LogToServer.prototype.logAccumulatedStatistics_ = function() {
-  var entry = remoting.ServerLogEntry.makeStats(this.statsAccumulator_,
-                                                this.connectionType_,
-                                                this.logEntryMode_);
-  if (entry) {
-    entry.addClientOSFields();
-    entry.addChromeVersionField();
-    entry.addWebappVersionField();
-    entry.addSessionIdField(this.sessionId_);
-    this.log_(entry);
-  }
-  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.
-  // Exclude time taken for authorization.
-  var sessionDurationInSeconds =
-      (new Date().getTime() - this.sessionStartTime_ -
-          this.authTotalTime_) / 1000.0;
-  entry.addSessionDuration(sessionDurationInSeconds);
-  entry.addApplicationId();
-  // The host-version/os/os-version will be blank for logs before a session has
-  // been created. For example, the signal-strategy log-entries won't have host
-  // version info.
-  entry.addHostVersion(this.hostVersion_);
-
-  // 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>';
-  this.signalStrategy_.sendMessage(stanza);
-};
-
-/**
- * Sets the session ID to a random string.
- */
-remoting.LogToServer.prototype.setSessionId = function() {
-  this.sessionId_ = remoting.LogToServer.generateSessionId_();
-  this.sessionIdGenerationTime_ = new Date().getTime();
-};
-
-/**
- * Clears the session ID.
- *
- * @private
- */
-remoting.LogToServer.prototype.clearSessionId_ = function() {
-  this.sessionId_ = '';
-  this.sessionIdGenerationTime_ = 0;
-};
-
-/**
- * Sets a new session ID, if the current session ID has reached its maximum age.
- *
- * This method also logs the old and new session IDs to the server, in separate
- * log entries.
- *
- * @private
- */
-remoting.LogToServer.prototype.maybeExpireSessionId_ = function() {
-  if ((this.sessionId_ != '') &&
-      (new Date().getTime() - this.sessionIdGenerationTime_ >=
-      remoting.Logger.MAX_SESSION_ID_AGE)) {
-    // Log the old session ID.
-    var entry = remoting.ServerLogEntry.makeSessionIdOld(this.sessionId_,
-                                                         this.logEntryMode_);
-    this.log_(entry);
-    // Generate a new session ID.
-    this.setSessionId();
-    // Log the new session ID.
-    entry = remoting.ServerLogEntry.makeSessionIdNew(this.sessionId_,
-                                                     this.logEntryMode_);
-    this.log_(entry);
-  }
-};
-
-/**
- * Generates a string that can be used as a session ID.
- *
- * @private
- * @return {string} a session ID
- */
-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('');
-};
-
-/**
- * @param {number} totalTime The value of time taken to complete authorization.
- * @return {void} Nothing.
- */
-remoting.LogToServer.prototype.setAuthTotalTime = function(totalTime) {
-  this.authTotalTime_ = totalTime;
-};
-
-/**
- * @param {string} hostVersion Version of the host for current session.
- * @return {void} Nothing.
- */
-remoting.LogToServer.prototype.setHostVersion = function(hostVersion) {
-  this.hostVersion_ = hostVersion;
-};
-
-/**
- * Stub.
- * @param {remoting.ChromotingEvent.Os} hostOS Type of the host OS for
-          current session.
- * @return {void} Nothing.
- */
-remoting.LogToServer.prototype.setHostOS = function(hostOS) {};
-
-/**
- * Stub
- * @override {remoting.Logger}
- */
-remoting.LogToServer.prototype.setHostStatusUpdateElapsedTime = function(time) {
-};
-
-/**
- * Stub.
- * @param {string} hostOSVersion Version of the host OS for current session.
- * @return {void} Nothing.
- */
-remoting.LogToServer.prototype.setHostOSVersion = function(hostOSVersion) {};
-
-/**
- * Stub.
- * @override {remoting.Logger}
- */
-remoting.LogToServer.prototype.setAuthMethod = function(authMethod) {};
diff --git a/remoting/webapp/base/js/logger.js b/remoting/webapp/base/js/logger.js
deleted file mode 100644
index 4a61f22..0000000
--- a/remoting/webapp/base/js/logger.js
+++ /dev/null
@@ -1,105 +0,0 @@
-// 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.
-
-
-/** @suppress {duplicate} */
-var remoting = remoting || {};
-
-(function() {
-
-'use strict';
-
-/**
- * @interface
- */
-remoting.Logger = function() {};
-
-/**
- * @param {number} totalTime The value of time taken to complete authorization.
- * @return {void} Nothing.
- */
-remoting.Logger.prototype.setAuthTotalTime = function(totalTime) {};
-
-/**
- * @param {string} hostVersion Version of the host for current session.
- * @return {void} Nothing.
- */
-remoting.Logger.prototype.setHostVersion = function(hostVersion) {};
-
-/**
- * @param {remoting.ChromotingEvent.Os} hostOS Type of the OS the host
- *        for the current session.
- * @return {void} Nothing.
- */
-remoting.Logger.prototype.setHostOS = function(hostOS) {};
-
-/**
- * @param {string} hostOSVersion Version of the host Os for current session.
- * @return {void} Nothing.
- */
-remoting.Logger.prototype.setHostOSVersion = function(hostOSVersion) {};
-
-/**
- * @param {number} time Time in milliseconds since the last host status update.
- * @return {void} Nothing.
- */
-remoting.Logger.prototype.setHostStatusUpdateElapsedTime = function(time) {};
-
-/**
- * Set the connection type (direct, stun relay).
- *
- * @param {string} connectionType
- */
-remoting.Logger.prototype.setConnectionType = function(connectionType) {};
-
-/**
- * @param {remoting.ChromotingEvent.Mode} mode
- */
-remoting.Logger.prototype.setLogEntryMode = function(mode) {};
-
-/**
- * @param {remoting.ChromotingEvent.AuthMethod} method
- */
-remoting.Logger.prototype.setAuthMethod = function(method) {};
-
-/**
- * @param {remoting.SignalStrategy.Type} strategyType
- * @param {remoting.FallbackSignalStrategy.Progress} progress
- */
-remoting.Logger.prototype.logSignalStrategyProgress =
-    function(strategyType, progress) {};
-
-/**
- * Logs a client session state change.
- *
- * @param {remoting.ClientSession.State} state
- * @param {!remoting.Error} connectionError
- * @param {?remoting.ChromotingEvent.XmppError} xmppError The XMPP error
- *     as described in http://xmpp.org/rfcs/rfc6120.html#stanzas-error.
- *     Set if the connecton error originates from the an XMPP stanza error.
- */
-remoting.Logger.prototype.logClientSessionStateChange =
-    function(state, connectionError, xmppError) {};
-
-/**
- * Logs connection statistics.
- * @param {Object<number>} stats The connection statistics
- */
-remoting.Logger.prototype.logStatistics = function(stats) {};
-
-
-/**
- * @return {string} The current session id. This is random GUID, refreshed
- *     every 24hrs.
- */
-remoting.Logger.prototype.getSessionId = function() {};
-
-// The maximum age of a session ID, in milliseconds.
-remoting.Logger.MAX_SESSION_ID_AGE = 24 * 60 * 60 * 1000;
-
-// The time over which to accumulate connection statistics before logging them
-// to the server, in milliseconds.
-remoting.Logger.CONNECTION_STATS_ACCUMULATE_TIME = 60 * 1000;
-
-})();
diff --git a/remoting/webapp/base/js/session_logger.js b/remoting/webapp/base/js/session_logger.js
index 34490f6..b3e7cdc 100644
--- a/remoting/webapp/base/js/session_logger.js
+++ b/remoting/webapp/base/js/session_logger.js
@@ -11,14 +11,13 @@ var remoting = remoting || {};
 'use strict';
 
 /**
- * This class defines a remoting.Logger implementation that generates
- * log entries in the format of remoting.ChromotingEvent.
+ * |remoting.SessionLogger| is responsible for reporting telemetry entries for
+ * a Chromoting session.
  *
  * @param {remoting.ChromotingEvent.Role} role
  * @param {function(!Object)} writeLogEntry
  *
  * @constructor
- * @implements {remoting.Logger}
  */
 remoting.SessionLogger = function(role, writeLogEntry) {
   /** @private */
@@ -64,53 +63,83 @@ remoting.SessionLogger.prototype.setEntryPoint = function(entryPoint) {
   this.entryPoint_ = entryPoint;
 };
 
-/** @override {remoting.Logger} */
+/**
+ * @param {number} totalTime The value of time taken to complete authorization.
+ * @return {void} Nothing.
+ */
 remoting.SessionLogger.prototype.setAuthTotalTime = function(totalTime) {
   this.authTotalTime_ = totalTime;
 };
 
-/** @override {remoting.Logger} */
+/**
+ * @param {string} hostVersion Version of the host for current session.
+ * @return {void} Nothing.
+ */
 remoting.SessionLogger.prototype.setHostVersion = function(hostVersion) {
   this.hostVersion_ = hostVersion;
 };
 
-/** @override {remoting.Logger} */
+/**
+ * @param {remoting.ChromotingEvent.Os} hostOS Type of the OS the host
+ *        for the current session.
+ * @return {void} Nothing.
+ */
 remoting.SessionLogger.prototype.setHostOS = function(hostOS) {
   this.hostOS_ = hostOS;
 };
 
-/** @override {remoting.Logger} */
+/**
+ * @param {string} hostOSVersion Version of the host Os for current session.
+ * @return {void} Nothing.
+ */
+remoting.SessionLogger.prototype.setHostOSVersion = function(hostOSVersion) {
+  this.hostOSVersion_ = hostOSVersion;
+};
+
+/**
+ * @param {number} time Time in milliseconds since the last host status update.
+ * @return {void} Nothing.
+ */
 remoting.SessionLogger.prototype.setHostStatusUpdateElapsedTime =
     function(time) {
   this.hostStatusUpdateElapsedTime_ = time;
 };
 
-/** @override {remoting.Logger} */
-remoting.SessionLogger.prototype.setHostOSVersion = function(hostOSVersion) {
-  this.hostOSVersion_ = hostOSVersion;
-};
-
-/** @override {remoting.Logger} */
+/**
+ * Set the connection type (direct, stun relay).
+ *
+ * @param {string} connectionType
+ */
 remoting.SessionLogger.prototype.setConnectionType = function(connectionType) {
   this.connectionType_ = toConnectionType(connectionType);
 };
 
-/** @override {remoting.Logger} */
+/**
+ * @param {remoting.ChromotingEvent.Mode} mode
+ */
 remoting.SessionLogger.prototype.setLogEntryMode = function(mode) {
   this.mode_ = mode;
 };
 
-/** @override {remoting.Logger} */
-remoting.SessionLogger.prototype.setAuthMethod = function(authMethod) {
-  this.authMethod_ = authMethod;
+/**
+ * @param {remoting.ChromotingEvent.AuthMethod} method
+ */
+remoting.SessionLogger.prototype.setAuthMethod = function(method) {
+  this.authMethod_ = method;
 };
 
-/** @override {remoting.Logger} */
+/**
+ * @return {string} The current session id. This is random GUID, refreshed
+ *     every 24hrs.
+ */
 remoting.SessionLogger.prototype.getSessionId = function() {
   return this.sessionId_;
 };
 
-/** @override {remoting.Logger} */
+/**
+ * @param {remoting.SignalStrategy.Type} strategyType
+ * @param {remoting.FallbackSignalStrategy.Progress} progress
+ */
 remoting.SessionLogger.prototype.logSignalStrategyProgress =
     function(strategyType, progress) {
   this.maybeExpireSessionId_();
@@ -123,7 +152,15 @@ remoting.SessionLogger.prototype.logSignalStrategyProgress =
   this.log_(entry);
 };
 
-/** @override {remoting.Logger} */
+/**
+ * Logs a client session state change.
+ *
+ * @param {remoting.ClientSession.State} state
+ * @param {!remoting.Error} stateError
+ * @param {?remoting.ChromotingEvent.XmppError} xmppError The XMPP error
+ *     as described in http://xmpp.org/rfcs/rfc6120.html#stanzas-error.
+ *     Set if the connecton error originates from the an XMPP stanza error.
+ */
 remoting.SessionLogger.prototype.logClientSessionStateChange = function(
     state, stateError, xmppError) {
   this.logSessionStateChange(
@@ -154,7 +191,11 @@ remoting.SessionLogger.prototype.logSessionStateChange = function(
   this.statsAccumulator_.empty();
 };
 
-/** @override {remoting.Logger} */
+/**
+ * Logs connection statistics.
+ *
+ * @param {Object<number>} stats The connection statistics
+ */
 remoting.SessionLogger.prototype.logStatistics = function(stats) {
   this.maybeExpireSessionId_();
   // Store the statistics.
@@ -162,7 +203,7 @@ remoting.SessionLogger.prototype.logStatistics = function(stats) {
   // Send statistics to the server if they've been accumulating for at least
   // 60 seconds.
   if (this.statsAccumulator_.getTimeSinceFirstValue() >=
-      remoting.Logger.CONNECTION_STATS_ACCUMULATE_TIME) {
+      remoting.SessionLogger.CONNECTION_STATS_ACCUMULATE_TIME) {
     this.logAccumulatedStatistics_();
   }
 };
@@ -277,6 +318,7 @@ remoting.SessionLogger.prototype.fillEvent_ = function(entry) {
 
 /**
  * Sends a log entry to the server.
+ *
  * @param {remoting.ChromotingEvent} entry
  * @private
  */
@@ -286,6 +328,7 @@ remoting.SessionLogger.prototype.log_ = function(entry) {
 
 /**
  * Sets the session ID to a random string.
+ *
  * @private
  */
 remoting.SessionLogger.prototype.setSessionId_ = function() {
@@ -316,7 +359,7 @@ remoting.SessionLogger.prototype.clearSessionId_ = function() {
 remoting.SessionLogger.prototype.maybeExpireSessionId_ = function() {
   if ((this.sessionId_ !== '') &&
       (new Date().getTime() - this.sessionIdGenerationTime_ >=
-      remoting.Logger.MAX_SESSION_ID_AGE)) {
+      remoting.SessionLogger.MAX_SESSION_ID_AGE)) {
     // Log the old session ID.
     var entry = this.makeSessionIdOld_();
     this.log_(entry);
@@ -419,4 +462,11 @@ function toConnectionType(type) {
   }
 }
 
+// The maximum age of a session ID, in milliseconds.
+remoting.SessionLogger.MAX_SESSION_ID_AGE = 24 * 60 * 60 * 1000;
+
+// The time over which to accumulate connection statistics before logging them
+// to the server, in milliseconds.
+remoting.SessionLogger.CONNECTION_STATS_ACCUMULATE_TIME = 60 * 1000;
+
 })();
diff --git a/remoting/webapp/base/js/session_logger_unittest.js b/remoting/webapp/base/js/session_logger_unittest.js
index 8bf4de8..4111ede 100644
--- a/remoting/webapp/base/js/session_logger_unittest.js
+++ b/remoting/webapp/base/js/session_logger_unittest.js
@@ -167,7 +167,7 @@ QUnit.test('logClientSessionStateChange() should handle sessionId change.',
   var oldSessionId = logger.getSessionId();
 
   // Expires the session id.
-  clock.tick(remoting.Logger.MAX_SESSION_ID_AGE + 100);
+  clock.tick(remoting.SessionLogger.MAX_SESSION_ID_AGE + 100);
 
   // Logs the event.
   logger.logClientSessionStateChange(
@@ -297,7 +297,7 @@ QUnit.test('logStatistics()', function(assert) {
 
   sinon.assert.notCalled(logWriterSpy);
   // Stats should only be accumulated at |CONNECTION_STATS_ACCUMULATE_TIME|.
-  clock.tick(remoting.Logger.CONNECTION_STATS_ACCUMULATE_TIME + 10);
+  clock.tick(remoting.SessionLogger.CONNECTION_STATS_ACCUMULATE_TIME + 10);
 
   logger.logStatistics({
     videoBandwidth: 3.0,
@@ -348,7 +348,7 @@ QUnit.test('logStatistics() should not log if all stats are zeros ',
     roundtripLatency: 0.0
   });
 
-  clock.tick(remoting.Logger.CONNECTION_STATS_ACCUMULATE_TIME + 10);
+  clock.tick(remoting.SessionLogger.CONNECTION_STATS_ACCUMULATE_TIME + 10);
 
   logger.logStatistics({
     videoBandwidth: 0.0,
diff --git a/remoting/webapp/crd/js/buffered_signal_strategy.js b/remoting/webapp/crd/js/buffered_signal_strategy.js
deleted file mode 100644
index 67ae2f9..0000000
--- a/remoting/webapp/crd/js/buffered_signal_strategy.js
+++ /dev/null
@@ -1,91 +0,0 @@
-// Copyright 2014 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';
-
-/** @suppress {duplicate} */
-var remoting = remoting || {};
-
-/**
- * Simplified SignalStrategy implementation that wraps an underlying signal
- * strategy and forwards messages when it is CONNECTED. It is used only to
- * log status messages during IT2Me connection setup, and only those methods
- * required for that are implemented.
- *
- * TODO(jamiewalch): Remove this class once a signal strategy is no longer
- *     required for logging (crbug.com/497269).
- *
- * @constructor
- * @param {remoting.SignalStrategy} underlying The underlying implementation.
- * @implements {remoting.SignalStrategy}
- */
-remoting.BufferedSignalStrategy = function(underlying) {
-  /** @private */
-  this.underlying_ = underlying;
-  /** @private {Array<string>} */
-  this.pendingMessages_ = [];
-
-  this.underlying_.setStateChangedCallback(this.flush_.bind(this));
-};
-
-remoting.BufferedSignalStrategy.prototype.dispose = function() {
-  this.underlying_.dispose();
-};
-
-/**
- * Sends a message. Can be called only in CONNECTED state.
- * @param {string} message
- */
-remoting.BufferedSignalStrategy.prototype.sendMessage = function(message) {
-  this.pendingMessages_.push(message);
-  this.flush_();
-};
-
-/**
- * If the underlying implementation is connected, flush all pending messages.
- * @private
- */
-remoting.BufferedSignalStrategy.prototype.flush_ = function() {
-  if (this.underlying_.getState() !== remoting.SignalStrategy.State.CONNECTED) {
-    return;
-  }
-  for (var i = 0; i < this.pendingMessages_.length; ++i) {
-    this.underlying_.sendMessage(this.pendingMessages_[i]);
-  }
-  this.pendingMessages_ = [];
-};
-
-
-// The following methods are not used by LogToServer and are not implemented.
-
-remoting.BufferedSignalStrategy.prototype.setStateChangedCallback =
-    function(onStateChangedCallback) {
-  console.error('Unexpected setStateChangedCallback().');
-};
-
-remoting.BufferedSignalStrategy.prototype.setIncomingStanzaCallback =
-    function(onIncomingStanzaCallback) {
-  console.error('Unexpected setIncomingStanzaCallback().');
-};
-
-remoting.BufferedSignalStrategy.prototype.connect =
-    function(server, username, authToken) {
-  console.error('Unexpected connect().');
-};
-
-remoting.BufferedSignalStrategy.prototype.getState = function() {
-  console.error('Unexpected getState().');
-};
-
-remoting.BufferedSignalStrategy.prototype.getError = function() {
-  console.error('Unexpected getError().');
-};
-
-remoting.BufferedSignalStrategy.prototype.getJid = function() {
-  console.error('Unexpected getJid().');
-};
-
-remoting.BufferedSignalStrategy.prototype.getType = function() {
-  console.error('Unexpected getType().');
-};
diff --git a/remoting/webapp/crd/js/host_screen.js b/remoting/webapp/crd/js/host_screen.js
index b0b61b9..56890d7 100644
--- a/remoting/webapp/crd/js/host_screen.js
+++ b/remoting/webapp/crd/js/host_screen.js
@@ -24,7 +24,7 @@ var hostSession_ = null;
 var lastShareWasCancelled_ = false;
 
 /**
- * @type {remoting.LogToServer} Logging instance for IT2Me host connection
+ * @type {remoting.SessionLogger} Logging instance for IT2Me host connection
  *     status.
  */
 var it2meLogger = null;
@@ -36,10 +36,11 @@ var it2meLogger = null;
  * to install them if necessary.
  */
 remoting.tryShare = function() {
-  ensureIT2MeLogger_();
-  it2meLogger.setSessionId();
-  it2meLogger.logClientSessionStateChange(
-      remoting.ClientSession.State.INITIALIZING, remoting.Error.none(), null);
+  it2meLogger = createLogger_();
+  it2meLogger.logSessionStateChange(
+      remoting.ChromotingEvent.SessionState.STARTED,
+      remoting.ChromotingEvent.ConnectionError.NONE,
+      null);
 
   /** @type {remoting.It2MeHostFacade} */
   var hostFacade = new remoting.It2MeHostFacade();
@@ -92,8 +93,10 @@ remoting.tryShareWithToken_ = function(hostFacade, token) {
   lastShareWasCancelled_ = false;
   onNatTraversalPolicyChanged_(true);  // Hide warning by default.
   remoting.setMode(remoting.AppMode.HOST_WAITING_FOR_CODE);
-  it2meLogger.logClientSessionStateChange(
-      remoting.ClientSession.State.CONNECTING, remoting.Error.none(), null);
+  it2meLogger.logSessionStateChange(
+      remoting.ChromotingEvent.SessionState.CONNECTING,
+      remoting.ChromotingEvent.ConnectionError.NONE,
+      null);
   document.getElementById('cancel-share-button').disabled = false;
   disableTimeoutCountdown_();
 
@@ -206,17 +209,19 @@ function logDebugInfo_(msg) {
 function showShareError_(error) {
   if (error.hasTag(remoting.Error.Tag.CANCELLED)) {
     remoting.setMode(remoting.AppMode.HOME);
-    it2meLogger.logClientSessionStateChange(
-        remoting.ClientSession.State.CONNECTION_CANCELED,
-        remoting.Error.none(),
+    it2meLogger.logSessionStateChange(
+        remoting.ChromotingEvent.SessionState.CONNECTION_CANCELED,
+        remoting.ChromotingEvent.ConnectionError.NONE,
         null);
   } else {
     var errorDiv = document.getElementById('host-plugin-error');
     l10n.localizeElementFromTag(errorDiv, error.getTag());
     console.error('Sharing error: ' + error.toString());
     remoting.setMode(remoting.AppMode.HOST_SHARE_FAILED);
-    it2meLogger.logClientSessionStateChange(
-        remoting.ClientSession.State.FAILED, error, null);
+    it2meLogger.logSessionStateChange(
+        remoting.ChromotingEvent.SessionState.CONNECTION_FAILED,
+        error.toConnectionError(),
+        null);
   }
 
   cleanUp();
@@ -247,9 +252,9 @@ remoting.cancelShare = function() {
   remoting.lastShareWasCancelled = true;
   try {
     hostSession_.disconnect();
-    it2meLogger.logClientSessionStateChange(
-        remoting.ClientSession.State.CONNECTION_CANCELED,
-        remoting.Error.none(),
+    it2meLogger.logSessionStateChange(
+        remoting.ChromotingEvent.SessionState.CONNECTION_CANCELED,
+        remoting.ChromotingEvent.ConnectionError.NONE,
         null);
   } catch (/** @type {*} */ error) {
     console.error('Error disconnecting: ' + error +
@@ -360,26 +365,17 @@ function onNatTraversalPolicyChanged_(enabled) {
 }
 
 /**
- * Create an IT2Me LogToServer instance if one does not already exist.
+ * Create an IT2Me SessionLogger instance.
+ *
+ * @return {remoting.SessionLogger}
  */
-function ensureIT2MeLogger_() {
-  if (it2meLogger) {
-    return;
-  }
-
-  var xmppConnection = new remoting.XmppConnection();
-  var tokenPromise = remoting.identity.getToken();
-  var emailPromise = remoting.identity.getEmail();
-  tokenPromise.then(function(/** string */ token) {
-    emailPromise.then(function(/** string */ email) {
-      xmppConnection.connect(remoting.settings.XMPP_SERVER, email, token);
-    });
-  });
-
-  var bufferedSignalStrategy =
-      new remoting.BufferedSignalStrategy(xmppConnection);
-  it2meLogger = new remoting.LogToServer(bufferedSignalStrategy, true);
-  it2meLogger.setLogEntryMode(remoting.ChromotingEvent.Mode.IT2ME);
+function createLogger_() {
+  // Create a new logger for each session to refresh the session id.
+  var logger = new remoting.SessionLogger(
+      remoting.ChromotingEvent.Role.HOST,
+      remoting.TelemetryEventWriter.Client.write);
+  logger.setLogEntryMode(remoting.ChromotingEvent.Mode.IT2ME);
+  return logger;
 }
 
 })();
diff --git a/remoting/webapp/files.gni b/remoting/webapp/files.gni
index 261d5a6..8fdc8d1 100644
--- a/remoting/webapp/files.gni
+++ b/remoting/webapp/files.gni
@@ -184,6 +184,7 @@ remoting_webapp_shared_js_core_files = [
   "base/js/application.js",
   "base/js/base.js",
   "base/js/callstack.js",
+  "base/js/chromoting_event.js",
   "base/js/console_wrapper.js",
   "base/js/ipc.js",
   "base/js/modal_dialogs.js",
@@ -208,11 +209,7 @@ remoting_webapp_shared_js_host_files = [
 
 # Logging and stats JavaScript files.
 remoting_webapp_shared_js_logging_files = [
-  "base/js/chromoting_event.js",
   "base/js/format_iq.js",
-  "base/js/logger.js",
-  "base/js/log_to_server.js",
-  "base/js/server_log_entry.js",
   "base/js/session_logger.js",
   "base/js/stats_accumulator.js",
 ]
@@ -275,7 +272,6 @@ remoting_webapp_js_gnubby_auth_files = [ "crd/js/gnubby_auth_handler.js" ]
 # Files for controlling the local machine as a host.
 # Includes both it2me and me2me files.
 remoting_webapp_js_host_control_files = [
-  "crd/js/buffered_signal_strategy.js",
   "crd/js/host_controller.js",
   "crd/js/host_daemon_facade.js",
   "crd/js/host_screen.js",
@@ -291,7 +287,6 @@ remoting_webapp_js_host_control_files = [
 # Files for controlling the local it2me host.
 # Included by public_session.html.
 remoting_webapp_js_it2me_host_control_files = [
-  "crd/js/buffered_signal_strategy.js",
   "crd/js/host_screen.js",
   "crd/js/host_session.js",
   "crd/js/host_install_dialog.js",
@@ -480,7 +475,9 @@ remoting_webapp_wcs_sandbox_html_js_files = [
 remoting_webapp_wcs_sandbox_html_all_js_files =
     remoting_webapp_wcs_sandbox_html_js_files
 remoting_webapp_wcs_sandbox_html_all_js_files += [
+  "base/js/chromoting_event.js",
   "base/js/error.js",
+  "base/js/platform.js",
   "base/js/plugin_settings.js",
 ]