Adding opt out and previews type information to DRP pingback

components/data_reduction_proxy/core/browser/data_reduction_proxy_network_delegate.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 "components/data_reduction_proxy/core/browser/data_reduction_proxy_network_delegate.h"
 
 #include <limits>
 #include <utility>
 
 #include "base/memory/ptr_util.h"
@@ skipping 373 matching lines @@
       request->response_headers()
           ? request->response_headers()->GetInt64HeaderValue(
                 "x-original-content-length")
           : -1;
 
   CalculateAndRecordDataUsage(*request, request_type);
 
   RecordContentLength(*request, request_type, original_content_length);
 }
 
+void DataReductionProxyNetworkDelegate::OnHeadersReceivedInternal(
+    net::URLRequest* request,
+    const net::CompletionCallback& callback,
+    const net::HttpResponseHeaders* original_response_headers,

[bengr, 2017/04/20 01:02:33]

Is this guaranteed to be non-null?

[RyanSturm, 2017/04/20 20:25:45]

I can't find any guarantees. The fact that it is a const* makes me want to null
check it. I added an early return instead of multiple checks.

+    scoped_refptr<net::HttpResponseHeaders>* override_response_headers,
+    GURL* allowed_unsafe_redirect_url) {
+  if (original_response_headers &&
+      IsEmptyImagePreview(*original_response_headers)) {
+    DataReductionProxyData* data =
+        DataReductionProxyData::GetDataAndCreateIfNecessary(request);
+    data->set_lofi_received(true);
+  } else if (original_response_headers &&
+             IsLitePagePreview(*original_response_headers)) {
+    DataReductionProxyData* data =
+        DataReductionProxyData::GetDataAndCreateIfNecessary(request);
+    data->set_lite_page_received(true);
+  }
+}
+
 void DataReductionProxyNetworkDelegate::CalculateAndRecordDataUsage(
     const net::URLRequest& request,
     DataReductionProxyRequestType request_type) {
   DCHECK(thread_checker_.CalledOnValidThread());
   int64_t data_used = request.GetTotalReceivedBytes();
 
   // Estimate how many bytes would have been used if the DataReductionProxy was
   // not used, and record the data usage.
   int64_t original_size = data_used;
 
@@ skipping 141 matching lines @@
 
   request_headers->RemoveHeader(net::HttpRequestHeaders::kAcceptEncoding);
   if (!header_value.empty())
     header_value += ", ";
   header_value += kBrotli;
   request_headers->SetHeader(net::HttpRequestHeaders::kAcceptEncoding,
                              header_value);
 }
 
 }  // namespace data_reduction_proxy