Lo-Fi snackbar should only be shown for the first q=low response of a page

components/data_reduction_proxy/core/browser/data_reduction_proxy_network_delegate.cc

Index: components/data_reduction_proxy/core/browser/data_reduction_proxy_network_delegate.cc
diff --git a/components/data_reduction_proxy/core/browser/data_reduction_proxy_network_delegate.cc b/components/data_reduction_proxy/core/browser/data_reduction_proxy_network_delegate.cc
index f9983391776cef8decdde25b48d1104ed094fcb9..0222d8cf4995ffda51aac50cb75f39bdf99e4fb7 100644
--- a/components/data_reduction_proxy/core/browser/data_reduction_proxy_network_delegate.cc
+++ b/components/data_reduction_proxy/core/browser/data_reduction_proxy_network_delegate.cc
@@ -202,6 +202,13 @@ void DataReductionProxyNetworkDelegate::OnCompletedInternal(
   if (data_reduction_proxy_bypass_stats_)
     data_reduction_proxy_bypass_stats_->OnUrlRequestCompleted(request, started);
 
+  if (data_reduction_proxy_io_data_ && request->response_info().headers &&
+      request->response_headers()->HasHeaderValue(
+          chrome_proxy_header(), chrome_proxy_lo_fi_directive())) {
+    data_reduction_proxy_io_data_->lofi_ui_service()->OnLoFiReponseReceived(
+        *request);
+  }
+
   // For better accuracy, we use the actual bytes read instead of the length
   // specified with the Content-Length header, which may be inaccurate,
   // or missing, as is the case with chunked encoding.