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 6fad5780175974502b1a268806d010f6a2a8a750..06d62fbfc2e2ff0fa84227b9a3ce7b50d9b1d080 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::MessageLoopProxy* origin_loop);
   ~NetworkDelegateErrorObserver() override;
 
+  static scoped_ptr<ProxyResolverErrorObserver> Create(
+      NetworkDelegate* network_delegate,
+      const scoped_refptr<base::MessageLoopProxy>& origin_loop);
+
   // ProxyResolverErrorObserver implementation.
   void OnPACScriptError(int line_number, const base::string16& error) override;