Implement and test CanonicalCookie::IsCanonical()

net/cookies/canonical_cookie.h

 // Copyright (c) 2012 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 NET_COOKIES_CANONICAL_COOKIE_H_
 #define NET_COOKIES_CANONICAL_COOKIE_H_
 
 #include <memory>
 #include <string>
 #include <vector>
@@ skipping 126 matching lines @@
   // Returns true if the cookie is less than |other|, considering only name,
   // domain and path. In particular, two equivalent cookies (see IsEquivalent())
   // are identical for PartialCompare().
   bool PartialCompare(const CanonicalCookie& other) const;
 
   // Returns true if the cookie is less than |other|, considering all fields.
   // FullCompare() is consistent with PartialCompare(): cookies sorted using
   // FullCompare() are also sorted with respect to PartialCompare().
   bool FullCompare(const CanonicalCookie& other) const;
 
+  // Return whether this object is a valid CanonicalCookie().  Invalid
+  // cookies may be constructed by the detailed constructor.
+  // A cookie is considered canonical if-and-only-if:
+  // * It can be created by CanonicalCookie::Create, or
+  // * It is identical to a cookie created by CanonicalCookie::Create except
+  //   that the creation time is null, or
+  // * It can be derived from a cookie created by CanonicalCookie::Create by
+  //   entry into and retrieval from a cookie store (specifically, this means
+  //   by the setting of an creation time in place of a null creation time, and
+  //   the setting of a last access time).
+  // An additional requirement on a CanonicalCookie is that if the last
+  // access time is non-null, the creation time must also be non-null and
+  // greater than the last access time.
+  bool IsCanonical() const;
+
  private:
   FRIEND_TEST_ALL_PREFIXES(CanonicalCookieTest, TestPrefixHistograms);
 
   // The special cookie prefixes as defined in
   // https://tools.ietf.org/html/draft-west-cookie-prefixes
   //
   // This enum is being histogrammed; do not reorder or remove values.
   enum CookiePrefix {
     COOKIE_PREFIX_NONE = 0,
     COOKIE_PREFIX_SECURE,
@@ skipping 28 matching lines @@
   bool httponly_;
   CookieSameSite same_site_;
   CookiePriority priority_;
 };
 
 typedef std::vector<CanonicalCookie> CookieList;
 
 }  // namespace net
 
 #endif  // NET_COOKIES_CANONICAL_COOKIE_H_