Use NESTABLE_ASYNC APIs to get NetLog data into Tracing

chrome/browser/net/chrome_net_log.cc

 // 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.
 
 #include "chrome/browser/net/chrome_net_log.h"
 
 #include <stdio.h>
 
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/values.h"
 #include "chrome/browser/net/net_log_temp_file.h"
 #include "chrome/browser/ui/webui/net_internals/net_internals_ui.h"
 #include "chrome/common/chrome_switches.h"
 #include "content/public/common/content_switches.h"
 #include "net/base/net_log_logger.h"
+#include "net/base/trace_net_log_observer.h"
 
 ChromeNetLog::ChromeNetLog()
     : net_log_temp_file_(new NetLogTempFile(this)) {
   const CommandLine* command_line = CommandLine::ForCurrentProcess();
   // Adjust base log level based on command line switch, if present.
   // This is done before adding any observers so the call to UpdateLogLevel when
   // an observers is added will set |effective_log_level_| correctly.
   if (command_line->HasSwitch(switches::kNetLogLevel)) {
     std::string log_level_string =
         command_line->GetSwitchValueASCII(switches::kNetLogLevel);
@@ skipping 23 matching lines @@
 
     if (file == NULL) {
       LOG(ERROR) << "Could not open file " << log_path.value()
                  << " for net logging";
     } else {
       scoped_ptr<base::Value> constants(NetInternalsUI::GetConstants());
       net_log_logger_.reset(new net::NetLogLogger(file, *constants));
       net_log_logger_->StartObserving(this);
     }
   }
+
+  trace_net_log_observer_.reset(new net::TraceNetLogObserver());
+  trace_net_log_observer_->WatchForTraceStart(this);
 }
 
 ChromeNetLog::~ChromeNetLog() {
   net_log_temp_file_.reset();
   // Remove the observers we own before we're destroyed.
   if (net_log_logger_)
     RemoveThreadSafeObserver(net_log_logger_.get());
+  if (trace_net_log_observer_) {
+    trace_net_log_observer_->StopWatchForTraceStart();
+  }

[mmenke, 2014/08/15 20:42:53]

nit:  Don't use braces on if's when the conditional and the body are both one
line, and there's no else clause.

[xunjieli, 2014/08/15 21:55:15]

Done. Thanks!

 }