Add a referrer class to be used in the browser process whenever passing around referrsr

content/browser/tab_contents/referrer.cc

+// Copyright (c) 2011 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 <iostream>
+
+#include "content/browser/tab_contents/referrer.h"
+
+using WebKit::WebReferrerPolicy;
+
+namespace content {
+
+Referrer::Referrer(const GURL& url,
+                   WebReferrerPolicy policy)
+    : url_(url),
+      policy_(policy) {
+}
+
+Referrer::Referrer()
+    : policy_(WebKit::WebReferrerPolicyDefault) {
+}
+
+std::ostream& operator<<(std::ostream& out, const Referrer& referrer) {
+  return out << referrer.url();
+}
+
+}  // namespace