Make original_response_headers parameter of NetworkDelegate::OnHeadersReceived const

net/base/network_delegate.cc

Index: net/base/network_delegate.cc
diff --git a/net/base/network_delegate.cc b/net/base/network_delegate.cc
index ea7facfd35b0ce6162454773534e8c474cc8d3f4..539d9877530f3f7709452f26487d2a497c235eea 100644
--- a/net/base/network_delegate.cc
+++ b/net/base/network_delegate.cc
@@ -37,7 +37,7 @@ void NetworkDelegate::NotifySendHeaders(URLRequest* request,
 int NetworkDelegate::NotifyHeadersReceived(
     URLRequest* request,
     const CompletionCallback& callback,
-    HttpResponseHeaders* original_response_headers,
+    const HttpResponseHeaders* original_response_headers,
     scoped_refptr<HttpResponseHeaders>* override_response_headers) {
   DCHECK(CalledOnValidThread());
   DCHECK(original_response_headers);