Move DevToolsNetLogObserver to c/b/loader and create stub of network service interface

content/browser/devtools/devtools_netlog_observer.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 CONTENT_BROWSER_DEVTOOLS_DEVTOOLS_NETLOG_OBSERVER_H_
-#define CONTENT_BROWSER_DEVTOOLS_DEVTOOLS_NETLOG_OBSERVER_H_
-
-#include <stdint.h>
-
-#include "base/containers/hash_tables.h"
-#include "base/macros.h"
-#include "base/memory/ref_counted.h"
-#include "content/public/common/resource_devtools_info.h"
-#include "net/log/net_log.h"
-
-namespace net {
-class URLRequest;
-}  // namespace net
-
-namespace content {
-struct ResourceResponse;
-
-// DevToolsNetLogObserver watches the NetLog event stream and collects the
-// stuff that may be of interest to DevTools. Currently, this only includes
-// actual HTTP/SPDY headers sent and received over the network.
-//
-// As DevToolsNetLogObserver shares live data with objects that live on the
-// IO Thread, it must also reside on the IO Thread.  Only OnAddEntry can be
-// called from other threads.
-class DevToolsNetLogObserver : public net::NetLog::ThreadSafeObserver {
-  typedef ResourceDevToolsInfo ResourceInfo;
-
- public:
-  // net::NetLog::ThreadSafeObserver implementation:
-  void OnAddEntry(const net::NetLog::Entry& entry) override;
-
-  void OnAddURLRequestEntry(const net::NetLog::Entry& entry);
-
-  static void Attach();
-  static void Detach();
-
-  // Must be called on the IO thread. May return NULL if no observers
-  // are active.
-  static DevToolsNetLogObserver* GetInstance();
-  static void PopulateResponseInfo(net::URLRequest*,
-                                   ResourceResponse*);
-
- private:
-  static DevToolsNetLogObserver* instance_;
-
-  DevToolsNetLogObserver();
-  ~DevToolsNetLogObserver() override;
-
-  ResourceInfo* GetResourceInfo(uint32_t id);
-
-  typedef base::hash_map<uint32_t, scoped_refptr<ResourceInfo>>
-      RequestToInfoMap;
-  RequestToInfoMap request_to_info_;
-
-  DISALLOW_COPY_AND_ASSIGN(DevToolsNetLogObserver);
-};
-
-}  // namespace content
-
-#endif  // CONTENT_BROWSER_DEVTOOLS_DEVTOOLS_NETLOG_OBSERVER_H_