Loosen strict 'Secure' checks for non-overlapping paths.

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 85 matching lines @@
   // having been canonicalized (in
   // GetCookieDomainWithString->CanonicalizeHost).
   bool IsEquivalent(const CanonicalCookie& ecc) const {
     // It seems like it would make sense to take secure and httponly into
     // account, but the RFC doesn't specify this.
     // NOTE: Keep this logic in-sync with TrimDuplicateCookiesForHost().
     return (name_ == ecc.Name() && domain_ == ecc.Domain()
             && path_ == ecc.Path());
   }
 
-  // Checks if two cookies have the same name and domain-match per RFC 6265.
-  // Note that this purposefully ignores paths, and that this function is
-  // guaranteed to return |true| for a superset of the inputs that
-  // IsEquivalent() above returns |true| for.
+  // Checks a looser set of equivalency rules than 'IsEquivalent()' in order
+  // to support the stricter 'Secure' behaviors specified in
+  // https://tools.ietf.org/html/draft-ietf-httpbis-cookie-alone#section-3
   //
-  // This is needed for the updates to RFC6265 as per
-  // https://tools.ietf.org/html/draft-west-leave-secure-cookies-alone.
+  // Returns 'true' if this cookie's name matches |ecc|, and this cookie is
+  // a domain-match for |ecc| (or vice versa), and |ecc|'s path is "on" this
+  // cookie's path (as per 'IsOnPath()').

[jww, 2016/09/06 22:45:10]

nit: Maybe make a more explicit note that this is not a symmetric check? It took
me a minute to fully grok that this is one purpose with the path change.

   bool IsEquivalentForSecureCookieMatching(const CanonicalCookie& ecc) const;
 
   void SetLastAccessDate(const base::Time& date) {
     last_access_date_ = date;
   }
 
   // Returns true if the given |url_path| path-matches the cookie-path as
   // described in section 5.1.4 in RFC 6265.
   bool IsOnPath(const std::string& url_path) const;
 
@@ skipping 84 matching lines @@
   bool httponly_;
   CookieSameSite same_site_;
   CookiePriority priority_;
 };
 
 typedef std::vector<CanonicalCookie> CookieList;
 
 }  // namespace net
 
 #endif  // NET_COOKIES_CANONICAL_COOKIE_H_