Adding DRP specfic UMA for FirstContentfulPaint

chrome/browser/renderer_host/chrome_navigation_data.cc

+// Copyright 2016 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 "chrome/browser/renderer_host/chrome_navigation_data.h"
+
+#include "components/data_reduction_proxy/core/browser/data_reduction_proxy_data.h"
+
+ChromeNavigationData::ChromeNavigationData() {}
+
+ChromeNavigationData::~ChromeNavigationData() {}
+
+std::unique_ptr<content::NavigationData> ChromeNavigationData::Clone() const {
+  std::unique_ptr<ChromeNavigationData> copy(new ChromeNavigationData());
+  if (data_reduction_proxy_data_)
+    copy->SetDataReductionProxyData(data_reduction_proxy_data_->DeepCopy());
+  return std::move(copy);
+}