Notify NetworkDelegate when bytes have been sent over the network.

net/base/network_delegate.h

Index: net/base/network_delegate.h
diff --git a/net/base/network_delegate.h b/net/base/network_delegate.h
index 3a29e26c9f7695a2b7a83fe59bb73f695c6ebf97..cad221e99db28d8395ad3f35ccfeb196d8e1db55 100644
--- a/net/base/network_delegate.h
+++ b/net/base/network_delegate.h
@@ -89,6 +89,7 @@ class NET_EXPORT NetworkDelegate : public base::NonThreadSafe {
   void NotifyResponseStarted(URLRequest* request);
   void NotifyNetworkBytesReceived(const URLRequest& request,
                                   int64_t bytes_received);
+  void NotifyNetworkBytesSent(const URLRequest& request, int64_t bytes_sent);
   void NotifyCompleted(URLRequest* request, bool started);
   void NotifyURLRequestDestroyed(URLRequest* request);
   void NotifyURLRequestJobOrphaned(URLRequest* request);
@@ -213,6 +214,16 @@ class NET_EXPORT NetworkDelegate : public base::NonThreadSafe {
   virtual void OnNetworkBytesReceived(const URLRequest& request,
                                       int64_t bytes_received) = 0;
 
+  // Called when bytes are sent over the network, such as when sending request
+  // headers or uploading request body bytes. This includes localhost requests.
+  // |bytes_sent| is the number of bytes measured at the application layer that
+  // have been sent over the network for this request since the last time
+  // OnNetworkBytesSent was called. |bytes_sent| will always be greater than 0.
+  // Currently, this is only implemented for HTTP transactions, and |bytes_sent|
+  // does not include TLS overhead or TCP retransmits.
+  virtual void OnNetworkBytesSent(const URLRequest& request,
+                                  int64_t bytes_sent) = 0;
+
   // Indicates that the URL request has been completed or failed.
   // |started| indicates whether the request has been started. If false,
   // some information like the socket address is not available.