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

content/browser/devtools/devtools_manager.cc

Index: content/browser/devtools/devtools_manager.cc
diff --git a/content/browser/devtools/devtools_manager.cc b/content/browser/devtools/devtools_manager.cc
index 8b269b265fdd89139337633dad2b80e826f3aed2..cdb6588d4b5b070635047151e1e4518b17b74789 100644
--- a/content/browser/devtools/devtools_manager.cc
+++ b/content/browser/devtools/devtools_manager.cc
@@ -6,8 +6,7 @@
 
 #include "base/bind.h"
 #include "base/message_loop/message_loop.h"
-#include "content/browser/devtools/devtools_agent_host_impl.h"
-#include "content/browser/devtools/devtools_netlog_observer.h"
+#include "content/browser/loader/network_service_interface.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/content_browser_client.h"
 
@@ -30,21 +29,13 @@ DevToolsManager::~DevToolsManager() {
 void DevToolsManager::AgentHostStateChanged(
     DevToolsAgentHostImpl* agent_host, bool attached) {
   if (attached) {
-    if (!attached_hosts_count_) {
-      BrowserThread::PostTask(
-          BrowserThread::IO,
-          FROM_HERE,
-          base::Bind(&DevToolsNetLogObserver::Attach));
-    }
+    if (!attached_hosts_count_)
+      NetworkServiceInterface::GetInstance()->EnableNetLogObserver();
     ++attached_hosts_count_;
   } else {
     --attached_hosts_count_;
-    if (!attached_hosts_count_) {
-      BrowserThread::PostTask(
-          BrowserThread::IO,
-          FROM_HERE,
-          base::Bind(&DevToolsNetLogObserver::Detach));
-    }
+    if (!attached_hosts_count_)
+      NetworkServiceInterface::GetInstance()->DisableNetLogObserver();
   }
 }