Store in memory cookies in a hash set instead of a list.

chrome/browser/browsing_data/canonical_cookie_hash.cc

+// Copyright 2014 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/browsing_data/canonical_cookie_hash.h"
+
+#include "base/hash.h"
+
+namespace canonical_cookie {
+
+size_t FastHash(const net::CanonicalCookie& cookie) {
+  return base::SuperFastHash(cookie.Name().c_str(), cookie.Name().size()) +
+         3 * base::SuperFastHash(cookie.Domain().c_str(),
+                                 cookie.Domain().size()) +
+         7 * base::SuperFastHash(cookie.Path().c_str(), cookie.Path().size());
+}
+
+};  // namespace canonical_cookie