Avoid using BrowserThread and ContentBrowserClient in NetLogObserver.

content/browser/devtools/devtools_manager.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 "content/browser/devtools/devtools_manager.h"
 
 #include "base/bind.h"
 #include "base/message_loop/message_loop.h"
 #include "content/browser/devtools/devtools_agent_host_impl.h"
 #include "content/browser/loader/netlog_observer.h"
@@ skipping 16 matching lines @@
   DCHECK(!attached_hosts_count_);
 }
 
 void DevToolsManager::AgentHostStateChanged(
     DevToolsAgentHostImpl* agent_host, bool attached) {
   if (attached) {
     if (!attached_hosts_count_) {
       BrowserThread::PostTask(
           BrowserThread::IO,
           FROM_HERE,
-          base::Bind(&NetLogObserver::Attach));
+          base::Bind(
+              &NetLogObserver::Attach,
+              GetContentClient()->browser()->GetNetLog(),
+              BrowserThread::GetTaskRunnerForThread(BrowserThread::IO)));
     }
     ++attached_hosts_count_;
   } else {
     --attached_hosts_count_;
     if (!attached_hosts_count_) {
       BrowserThread::PostTask(
           BrowserThread::IO,
           FROM_HERE,
           base::Bind(&NetLogObserver::Detach));
     }
   }
 }
 
 }  // namespace content