Add ProxyResolverFactoryV8Tracing.

net/proxy/network_delegate_error_observer.h

Index: net/proxy/network_delegate_error_observer.h
diff --git a/net/proxy/network_delegate_error_observer.h b/net/proxy/network_delegate_error_observer.h
index 2ae649c68a7bd767e557927b6d2f575290b891d1..2463913ff651aba04ee7a65da1166bfb622e5146 100644
--- a/net/proxy/network_delegate_error_observer.h
+++ b/net/proxy/network_delegate_error_observer.h
@@ -7,6 +7,7 @@
 
 #include "base/compiler_specific.h"
 #include "base/memory/ref_counted.h"
+#include "base/memory/scoped_ptr.h"
 #include "net/proxy/proxy_resolver_error_observer.h"
 
 namespace base {
@@ -26,6 +27,10 @@ class NET_EXPORT_PRIVATE NetworkDelegateErrorObserver
                                base::SingleThreadTaskRunner* origin_runner);
   ~NetworkDelegateErrorObserver() override;
 
+  static scoped_ptr<ProxyResolverErrorObserver> Create(
+      NetworkDelegate* network_delegate,
+      const scoped_refptr<base::SingleThreadTaskRunner>& origin_runner);
+
   // ProxyResolverErrorObserver implementation.
   void OnPACScriptError(int line_number, const base::string16& error) override;