Move data reduction proxy to Chrome-Proxy header for authentication

net/http/http_transaction_test_util.cc

Index: net/http/http_transaction_test_util.cc
diff --git a/net/http/http_transaction_test_util.cc b/net/http/http_transaction_test_util.cc
index f3d086c513399c5ecaecd3b6344464588833c16f..f54c99f3b4b2b3cbfec5f3eec11e9688a580e38f 100644
--- a/net/http/http_transaction_test_util.cc
+++ b/net/http/http_transaction_test_util.cc
@@ -424,6 +424,10 @@ void MockNetworkTransaction::SetBeforeNetworkStartCallback(
     const BeforeNetworkStartCallback& callback) {
 }
 
+void MockNetworkTransaction::SetBeforeProxyHeadersSentCallback(
+    const BeforeProxyHeadersSentCallback& callback) {
+}
+
 int MockNetworkTransaction::ResumeNetworkStart() {
   // Should not get here.
   return net::ERR_FAILED;