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

content/browser/tab_contents/referrer.h

+// 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.
+
+#ifndef CONTENT_BROWSER_TAB_CONTENTS_REFERRER_H_
+#define CONTENT_BROWSER_TAB_CONTENTS_REFERRER_H_
+#pragma once
+
+#include <iosfwd>
+
+#include "base/basictypes.h"
+#include "content/common/content_export.h"
+#include "googleurl/src/gurl.h"
+#include "third_party/WebKit/Source/WebKit/chromium/public/WebReferrerPolicy.h"
+
+namespace content {
+
+// This class holds a referrer URL, as well as the referrer policy to be
+// applied to this URL. When passing around referrers in the browser process,
+// that will eventually end up being used for URL requests, always use this
+// class.
+class CONTENT_EXPORT Referrer {
+ public:
+  Referrer(const GURL& referrer, WebKit::WebReferrerPolicy referrer_policy);
+  Referrer();
+
+  const GURL& referrer() const { return referrer_; }

[darin (slow to review), 2011/11/22 19:20:59]

nit: since the class is named Referrer, how about naming this method url()?  and
similarly drop the referrer_ prefix on policy().

[jochen (gone - plz use gerrit), 2011/11/22 19:54:47]

Done.

+  WebKit::WebReferrerPolicy referrer_policy() const { return referrer_policy_; }
+
+  bool operator!=(const Referrer& other) const {

[darin (slow to review), 2011/11/22 19:20:59]

nit: we usually don't provide operator overloads.  however, if you are going to
do this, then you should at least implement != in terms of ==, so that you are
not duplicating code.

 operator!=(...) {
   return !(a == b);
 }

also, i think it good c++ style to make operator== and operator!= be top-level
functions.  that way, you support type coercion for either the LHS or RHS of the
== operator.

[jochen (gone - plz use gerrit), 2011/11/22 19:54:47]

I'll drop this, since I'm not sure it's really needed anywhere

+    return referrer_ != other.referrer_ ||
+           referrer_policy_ != other.referrer_policy_;
+  }
+  bool operator==(const Referrer& other) const {
+    return referrer_ == other.referrer_ &&
+           referrer_policy_ == other.referrer_policy_;
+  }
+
+ private:
+  GURL referrer_;
+  WebKit::WebReferrerPolicy referrer_policy_;
+};
+
+// Stream operator so Referrer can be used in assertion statements.
+CONTENT_EXPORT std::ostream& operator<<(std::ostream& out,
+                                        const Referrer& referrer);
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_TAB_CONTENTS_REFERRER_H_