Notify NetworkDelegate when bytes have been sent over the network.

net/base/network_delegate_impl.cc

Index: net/base/network_delegate_impl.cc
diff --git a/net/base/network_delegate_impl.cc b/net/base/network_delegate_impl.cc
index 3cc8c2196c965dbd52e42ffcfdbff05448c95d01..1f220a7749f0830cd8ef2368387450012cf6ede3 100644
--- a/net/base/network_delegate_impl.cc
+++ b/net/base/network_delegate_impl.cc
@@ -40,6 +40,9 @@ void NetworkDelegateImpl::OnSendHeaders(URLRequest* request,
                                         const HttpRequestHeaders& headers) {
 }
 
+void NetworkDelegateImpl::OnNetworkBytesSent(const URLRequest& request,
+                                             int64_t bytes_sent) {}
+
 int NetworkDelegateImpl::OnHeadersReceived(
     URLRequest* request,
     const CompletionCallback& callback,