Add NetLog support to UDP sockets.

chrome/browser/resources/net_internals/source_tracker.js

 // Copyright (c) 2011 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.
 
 var SourceTracker = (function() {
   'use strict';
 
   /**
    * This class keeps track of all NetLog events.
    * It receives events from the browser and when loading a log file, and passes
@@ skipping 57 matching lines @@
 
     /**
      * Returns the number of events that were captured passively by the
      * browser prior to when the net-internals page was started.
      */
     getNumPassivelyCapturedEvents: function() {
       return this.numPassivelyCapturedEvents_;
     },
 
     /**
+     * Returns the description of the specified SourceEntry, or an empty string
+     * if it doesn't exist.
+     */
+    getDescription: function(id) {
+      var entry = this.getSourceEntry(id);
+      if (entry)
+        return entry.getDescription();
+      return '';
+    },
+
+    /**
      * Returns the specified SourceEntry.
      */
     getSourceEntry: function(id) {
       return this.sourceEntries_[id];
     },
 
     onReceivedPassiveLogEntries: function(logEntries) {
       // Due to an expected race condition, it is possible to receive actively
       // captured log entries before the passively logged entries are received.
       //
@@ skipping 123 matching lines @@
      *   ovserver.deleteAllSourceEntries()
      *   observer.onSecurityStrippingChanged()
      */
     addObserver: function(observer) {
       this.observers_.push(observer);
     }
   };
 
   return SourceTracker;
 })();