SameSite: Implement 'Strict'/'Lax' attribute parsing.

https://tools.ietf.org/html/draft-west-first-party-cookies-06 introduced
the notion of "Strict" or "Lax" enforcement of the "SameSite" attribute.
This patch implements the infrastructure changes necessary to support
that distinction, but does not yet implement the behavioral change
(that is, after this patch, `SameSite` will be rejected, while
`SameSite=Strict` and `SameSite=Lax` will have the same behavior that
`SameSite` alone has today).

Most of this patch is occupied with the fairly mechanical process of
swapping out a new 'CookieSameSite' enum for the existing boolean in
various constructors and setters. The most interesting piece is the
change to the storage backend, which now stores 0, 1, or 2 in the
database to represent the possible values, rather than 0 or 1 to
represent the boolean.

BUG=459154

Review URL: https://codereview.chromium.org/1773133002

Cr-Commit-Position: refs/heads/master@{#381201}

1 files changed, 1 insertions, 1 deletions

diff --git a/net/url_request/url_request_unittest.cc b/net/url_request/url_request_unittest.cc
index a2da83a..fef773d 100644
--- a/net/url_request/url_request_unittest.cc
+++ b/net/url_request/url_request_unittest.cc
@@ -2664,7 +2664,7 @@ TEST_F(URLRequestTest, SameSiteCookiesEnabled) {
   {
     TestDelegate d;
     scoped_ptr<URLRequest> req(default_context_.CreateRequest(
-        test_server.GetURL("/set-cookie?SameSiteCookieToSet=1;SameSite"),
+        test_server.GetURL("/set-cookie?SameSiteCookieToSet=1;SameSite=Strict"),
         DEFAULT_PRIORITY, &d));
     req->Start();
     base::RunLoop().Run();