Limit the number of captured events held by about:net-internals.

chrome/browser/resources/net_internals/browser_bridge.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.
 
 /**
  * This class provides a "bridge" for communicating between the javascript and
  * the browser.
  */
 var BrowserBridge = (function() {
   'use strict';
@@ skipping 47 matching lines @@
           new PollableDataHelper('onServiceProvidersChanged',
                                  this.sendGetServiceProviders.bind(this));
     }
     this.pollableDataHelpers_.prerenderInfo =
         new PollableDataHelper('onPrerenderInfoChanged',
                                this.sendGetPrerenderInfo.bind(this));
     this.pollableDataHelpers_.httpPipeliningStatus =
         new PollableDataHelper('onHttpPipeliningStatusChanged',
                                this.sendGetHttpPipeliningStatus.bind(this));
 
-    // NetLog entries are all sent to the |SourceTracker|, which both tracks
-    // them and manages its own observer list.
-    this.sourceTracker = new SourceTracker();
-
     // Setting this to true will cause messages from the browser to be ignored,
     // and no messages will be sent to the browser, either.  Intended for use
     // when viewing log files.
     this.disabled_ = false;
 
     // Interval id returned by window.setInterval for polling timer.
     this.pollIntervalId_ = null;
   }
 
   cr.addSingletonGetter(BrowserBridge);
@@ skipping 169 matching lines @@
         return;
       this[command](params);
     },
 
     receivedConstants: function(constants) {
       for (var i = 0; i < this.constantsObservers_.length; i++)
         this.constantsObservers_[i].onReceivedConstants(constants);
     },
 
     receivedLogEntries: function(logEntries) {
-      this.sourceTracker.onReceivedLogEntries(logEntries);
+      EventsTracker.getInstance().addLogEntries(logEntries);
     },
 
     receivedProxySettings: function(proxySettings) {
       this.pollableDataHelpers_.proxySettings.update(proxySettings);
     },
 
     receivedBadProxies: function(badProxies) {
       this.pollableDataHelpers_.badProxies.update(badProxies);
     },
 
@@ skipping 447 matching lines @@
       helper.removeObserver(this);
       --this.observingCount_;
       this.updatedData_[name] = data;
       if (this.observingCount_ == 0)
         this.callback_(this.updatedData_);
     }
   };
 
   return BrowserBridge;
 })();