Notify NetworkDelegate when bytes have been sent over the network.

net/base/layered_network_delegate.h

Index: net/base/layered_network_delegate.h
diff --git a/net/base/layered_network_delegate.h b/net/base/layered_network_delegate.h
index f5899e9b8733cd692bd666910992d58917af92c4..0172147787b1d5272e799641ee0044cdc636a6fc 100644
--- a/net/base/layered_network_delegate.h
+++ b/net/base/layered_network_delegate.h
@@ -56,6 +56,7 @@ class NET_EXPORT LayeredNetworkDelegate : public NetworkDelegate {
                                 HttpRequestHeaders* headers) final;
   void OnSendHeaders(URLRequest* request,
                      const HttpRequestHeaders& headers) final;
+  void OnNetworkBytesSent(const URLRequest& request, int64_t bytes_sent) final;
   int OnHeadersReceived(
       URLRequest* request,
       const CompletionCallback& callback,
@@ -113,6 +114,9 @@ class NET_EXPORT LayeredNetworkDelegate : public NetworkDelegate {
   virtual void OnSendHeadersInternal(URLRequest* request,
                                      const HttpRequestHeaders& headers);
 
+  virtual void OnNetworkBytesSentInternal(const URLRequest& request,
+                                          int64_t bytes_sent);
+
   virtual void OnHeadersReceivedInternal(
       URLRequest* request,
       const CompletionCallback& callback,