Use NESTABLE_ASYNC APIs to get NetLog data into Tracing

chrome/browser/net/chrome_net_log.h

 // 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.
 
 #ifndef CHROME_BROWSER_NET_CHROME_NET_LOG_H_
 #define CHROME_BROWSER_NET_CHROME_NET_LOG_H_
 
 #include "base/atomicops.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/observer_list.h"
 #include "base/synchronization/lock.h"
 #include "net/base/net_log.h"
 
 namespace net {
 class NetLogLogger;
+class TraceNetLogObserver;
 }
 
 class NetLogTempFile;
 
 // ChromeNetLog is an implementation of NetLog that adds file loggers
 // as its observers.
 class ChromeNetLog : public net::NetLog {
  public:
   ChromeNetLog();
   virtual ~ChromeNetLog();
 
   NetLogTempFile* net_log_temp_file() {
     return net_log_temp_file_.get();
   }
 
  private:
   scoped_ptr<net::NetLogLogger> net_log_logger_;
   scoped_ptr<NetLogTempFile> net_log_temp_file_;
 
+  scoped_ptr<net::TraceNetLogObserver> trace_net_log_observer_;
+
   DISALLOW_COPY_AND_ASSIGN(ChromeNetLog);
 };
 
 #endif  // CHROME_BROWSER_NET_CHROME_NET_LOG_H_