Notify NetworkDelegate when bytes have been received over the network.

net/base/network_delegate_impl.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "net/base/network_delegate_impl.h"
 
 #include "net/base/net_errors.h"
 
 namespace net {
 
@@ skipping 42 matching lines @@
                                            const GURL& new_location) {
 }
 
 void NetworkDelegateImpl::OnResponseStarted(URLRequest* request) {
 }
 
 void NetworkDelegateImpl::OnRawBytesRead(const URLRequest& request,
                                          int bytes_read) {
 }
 
+void NetworkDelegateImpl::OnNetworkBytesReceived(const URLRequest& request,

[bengr, 2015/08/17 21:30:39]

What's the argument for this approach instead of having request own a struct of
data usage statistics?

[sclittle, 2015/08/17 23:35:14]

This is just a way for consumers to be notified how many network bytes were
received, when they're received. We'll probably want to expose some data usage
statistics from the request as well, like GetTotalReceivedBytes() is right now.

The advantage of this style of notification is that consumers are notified when
bytes are read for a request, and they don't have to keep track of and compute
the delta bytes_received for a request in the consumer at each stage in the
request, e.g. between OnHeadersReceived() and OnRawBytesRead().

+                                                 int64 bytes_received) {}
+
 void NetworkDelegateImpl::OnCompleted(URLRequest* request, bool started) {
 }
 
 void NetworkDelegateImpl::OnURLRequestDestroyed(URLRequest* request) {
 }
 
 void NetworkDelegateImpl::OnPACScriptError(int line_number,
                                            const base::string16& error) {
 }
 
@@ skipping 32 matching lines @@
 }
 
 bool NetworkDelegateImpl::OnCancelURLRequestWithPolicyViolatingReferrerHeader(
     const URLRequest& request,
     const GURL& target_url,
     const GURL& referrer_url) const {
   return false;
 }
 
 }  // namespace net