Update NetLog to be thread safe.

net/base/forwarding_net_log.h

-// 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.
-
-#ifndef NET_BASE_FORWARDING_NET_LOG_H_
-#define NET_BASE_FORWARDING_NET_LOG_H_
-#pragma once
-
-#include "base/basictypes.h"
-#include "net/base/net_log.h"
-
-class MessageLoop;
-
-namespace net {
-
-// ForwardingNetLog is a wrapper that can be called on any thread, and will
-// forward any calls to NetLog::AddEntry() over to |impl| on the specified
-// message loop.
-//
-// This allows using a non-threadsafe NetLog implementation from another
-// thread.
-//
-// TODO(eroman): Explore making NetLog threadsafe and obviating the need
-//               for this class.
-class ForwardingNetLog : public NetLog {
- public:
-  // Both |impl| and |loop| must outlive the lifetime of this instance.
-  // |impl| will be operated only from |loop|.
-  ForwardingNetLog(NetLog* impl, MessageLoop* loop);
-
-  // On destruction any outstanding call to AddEntry() which didn't make
-  // it to |loop| yet will be cancelled.
-  ~ForwardingNetLog();
-
-  // NetLog methods:
-  virtual void AddEntry(EventType type,
-                        const base::TimeTicks& time,
-                        const Source& source,
-                        EventPhase phase,
-                        EventParameters* params);
-  virtual uint32 NextID();
-  virtual LogLevel GetLogLevel() const;
-
- private:
-  class Core;
-  scoped_refptr<Core> core_;
-
-  DISALLOW_COPY_AND_ASSIGN(ForwardingNetLog);
-};
-
-}  // namespace net
-
-#endif  // NET_BASE_FORWARDING_NET_LOG_H_
-