Update NetLog to be thread safe.

chrome/browser/resources/net_internals/main.js

 // Copyright (c) 2010 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.
 
 /**
  * Dictionary of constants (initialized by browser).
  */
 var LogEventType = null;
 var LogEventPhase = null;
 var ClientInfo = null;
@@ skipping 290 matching lines @@
 
 BrowserBridge.prototype.setLogLevel = function(logLevel) {
   chrome.send('setLogLevel', ['' + logLevel]);
 }
 
 //------------------------------------------------------------------------------
 // Messages received from the browser
 //------------------------------------------------------------------------------
 
 BrowserBridge.prototype.receivedLogEntry = function(logEntry) {
-  // Silently drop entries received before ready to receive them.
-  if (!this.areLogTypesReady_())
-    return;
   // Assign unique ID, if needed.
   if (logEntry.source.id == 0) {
     logEntry.source.id = this.nextSourcelessEventId_;
     --this.nextSourcelessEventId_;
   }
   this.capturedEvents_.push(logEntry);
   for (var i = 0; i < this.logObservers_.length; ++i)
     this.logObservers_[i].onLogEntryAdded(logEntry);
 };
 
@@ skipping 57 matching lines @@
 
 BrowserBridge.prototype.receivedSpdySessionInfo = function(spdySessionInfo) {
   this.pollableDataHelpers_.spdySessionInfo.update(spdySessionInfo);
 };
 
 BrowserBridge.prototype.receivedServiceProviders = function(serviceProviders) {
   this.pollableDataHelpers_.serviceProviders.update(serviceProviders);
 };
 
 BrowserBridge.prototype.receivedPassiveLogEntries = function(entries) {
-  this.numPassivelyCapturedEvents_ += entries.length;
+  // 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.deleteAllEvents();
+
+  this.numPassivelyCapturedEvents_ = entries.length;
   for (var i = 0; i < entries.length; ++i) {
     var entry = entries[i];
     entry.wasPassivelyCaptured = true;
     this.receivedLogEntry(entry);
   }
+
+  // Add back early actively captured events, if any.
+  for (var i = 0; i < earlyActivelyCapturedEvents.length; ++i) {
+    this.receivedLogEntry(earlyActivelyCapturedEvents[i]);
+  }
 };
 
 
 BrowserBridge.prototype.receivedStartConnectionTestSuite = function() {
   for (var i = 0; i < this.connectionTestsObservers_.length; ++i)
     this.connectionTestsObservers_[i].onStartedConnectionTestSuite();
 };
 
 BrowserBridge.prototype.receivedStartConnectionTestExperiment = function(
     experiment) {
@@ skipping 13 matching lines @@
 
 BrowserBridge.prototype.receivedCompletedConnectionTestSuite = function() {
   for (var i = 0; i < this.connectionTestsObservers_.length; ++i)
     this.connectionTestsObservers_[i].onCompletedConnectionTestSuite();
 };
 
 BrowserBridge.prototype.receivedHttpCacheInfo = function(info) {
   this.pollableDataHelpers_.httpCacheInfo.update(info);
 };
 
-BrowserBridge.prototype.areLogTypesReady_ = function() {
-  return (LogEventType  != null &&
-          LogEventPhase != null &&
-          LogSourceType != null);
-};
-
 //------------------------------------------------------------------------------
 
 /**
  * Adds a listener of log entries. |observer| will be called back when new log
  * data arrives, through:
  *
  *   observer.onLogEntryAdded(logEntry)
  */
 BrowserBridge.prototype.addLogObserver = function(observer) {
   this.logObservers_.push(observer);
@@ skipping 303 matching lines @@
   return true;
 };
 
 UpdateAllObserver.prototype.onDataReceived_ = function(helper, name, data) {
   helper.removeObserver(this);
   --this.observingCount_;
   this.updatedData_[name] = data;
   if (this.observingCount_ == 0)
     this.callback_(this.updatedData_);
 };