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.
 
 /**
  * This class keeps track of all NetLog events.
  * It receives events from the browser and when loading a log file, and passes
  * them on to all its observers.
  *
  * @constructor
@@ skipping 59 matching lines @@
   return this.numPassivelyCapturedEvents_;
 };
 
 /**
  * Returns the specified SourceEntry.
  */
 SourceTracker.prototype.getSourceEntry = function(id) {
   return this.sourceEntries_[id];
 };
 
+/**
+ * Returns the description of the specified SourceEntry, or an empty string if
+ * it doesn't exist.
+ */
+SourceTracker.prototype.getDescription = function(id) {
+  var entry = this.getSourceEntry(id);
+  if (entry)
+    return entry.getDescription();
+  return '';
+};
+
 SourceTracker.prototype.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.
   //
   // When that happens, we create a copy of the actively logged entries, delete
   // all entries, and, after handling all the passively logged entries, add back
   // the deleted actively logged entries.
   var earlyActivelyCapturedEvents = this.capturedEvents_.slice(0);
   if (earlyActivelyCapturedEvents.length > 0)
     this.deleteAllSourceEntries();
@@ skipping 114 matching lines @@
  * through:
  *
  *   observer.onSourceEntriesUpdated(sourceEntries)
  *   observer.deleteSourceEntries(sourceEntryIds)
  *   ovserver.deleteAllSourceEntries()
  *   observer.onSecurityStrippingChanged()
  */
 SourceTracker.prototype.addObserver = function(observer) {
   this.observers_.push(observer);
 };