Switch assertion in test=42 to follow latest 6265bis update.

Also, add a few more tests inspired by bingler@'s GitHub comments.

Previously, the cookie spec left an empty domain attribute as
undefined behavior with SHOULD-level guidance.
httpwg/http-extensions#1709 changes the
spec to require handling of a cookie as a host cookie when its
last domain attribute is empty. This matches the current behavior
of Firefox and Safari.

See httpwg/http-extensions#1332 for
more discussion.

Change-Id: Ibf4f243c929b11768ff406e940d6988a37434754
Bug: 1255273

cookies/attributes/resources/domain-child.sub.html

@@ -310,8 +310,8 @@
         },
         {
           cookie: `test=42; domain=${www1Host}; domain=`,
-          expected: "",
-          name: "No cookie returned for domain mismatch (with domain mismatch as first domain attribute and second a bare attribute)",
+          expected: "test=42",
+          name: "Cookie returned for bare domain attribute following mismatched domain attribute (after redirect to same-origin page).",
           location: `http://${wwwHost}:${port}/cookies/attributes/resources/path.html`,
         },
         {
@@ -332,6 +332,30 @@
           name: "Cookies with same name, path, and domain (differing only in leading '.') overwrite each other ('.' first)",
           location: `http://${wwwHost}:${port}/cookies/attributes/resources/path.html`,
         },
+        {
+          cookie: `test=46; domain=.`,
+          expected: "test=46",
+          name: "Domain with single . as value should be treated as host cookie",
+          location: `http://${wwwHost}:${port}/cookies/attributes/resources/path.html`,
+        },
+        {
+          cookie: ["test=47", `test=47b; domain=${host}`,`test=47b; domain=${www1Host}; domain=`],
+          expected: "test=47b; test=47b",
+          name: "Empty domain treated as host cookie 1",
+          location: `http://${wwwHost}:${port}/cookies/attributes/resources/path.html`,
+        },
+        {
+          cookie: ["test=48", `test=48b; domain=${host}`,`test=48b; domain=${host}; domain=`],
+          expected: "test=48b; test=48b",
+          name: "Empty domain treated as host cookie 2",
+          location: `http://${wwwHost}:${port}/cookies/attributes/resources/path.html`,
+        },
+        {
+          cookie: ["test=49", `test=49b; domain=${host}`,`test=49b; domain=`],
+          expected: "test=49b; test=49b",
+          name: "Empty domain treated as host cookie 3",
+          location: `http://${wwwHost}:${port}/cookies/attributes/resources/path.html`,
+        },
       ];
 
       for (const test of domainTests) {