Ignore cookies with invalid 'SameSite' attribute values.

net/cookies/parsed_cookie.cc

Index: net/cookies/parsed_cookie.cc
diff --git a/net/cookies/parsed_cookie.cc b/net/cookies/parsed_cookie.cc
index a6c1e950689b19a40ee1ae8318c55f82fa7a95b5..2175692f534a0ff8c4db3a65f898858a47da8a10 100644
--- a/net/cookies/parsed_cookie.cc
+++ b/net/cookies/parsed_cookie.cc
@@ -179,7 +179,7 @@ ParsedCookie::~ParsedCookie() {
 }
 
 bool ParsedCookie::IsValid() const {
-  return !pairs_.empty();
+  return !pairs_.empty() && IsSameSiteAttributeValid();
 }
 
 CookieSameSite ParsedCookie::SameSite() const {
@@ -506,4 +506,8 @@ void ParsedCookie::ClearAttributePair(size_t index) {
   pairs_.erase(pairs_.begin() + index);
 }
 
+bool ParsedCookie::IsSameSiteAttributeValid() const {
+  return same_site_index_ == 0 || SameSite() != CookieSameSite::DEFAULT_MODE;
+}
+
 }  // namespace