deleted file mode 100644
--- a/testing/web-platform/meta/webdriver/tests/cookies/add_cookie.py.ini
+++ /dev/null
@@ -1,16 +0,0 @@
-[add_cookie.py]
-  [test_add_domain_cookie]
-    expected: FAIL
-
-  [test_add_cookie_for_ip]
-    expected: FAIL
-
-  [test_add_non_session_cookie]
-    expected: FAIL
-
-  [test_add_session_cookie]
-    expected: FAIL
-
-  [test_add_session_cookie_with_leading_dot_character_in_domain]
-    expected: FAIL
-

--- a/testing/web-platform/tests/webdriver/tests/cookies/add_cookie.py
+++ b/testing/web-platform/tests/webdriver/tests/cookies/add_cookie.py
@@ -1,28 +1,27 @@
+from tests.support.asserts import assert_success
 from tests.support.fixtures import clear_all_cookies
 from datetime import datetime, timedelta
 
 def test_add_domain_cookie(session, url, server_config):
     session.url = url("/common/blank.html")
     clear_all_cookies(session)
     create_cookie_request = {
         "cookie": {
             "name": "hello",
             "value": "world",
-            "domain": server_config["domains"][""],
+            "domain": server_config["browser_host"],
             "path": "/",
             "httpOnly": False,
             "secure": False
         }
     }
     result = session.transport.send("POST", "session/%s/cookie" % session.session_id, create_cookie_request)
-    assert result.status == 200
-    assert "value" in result.body
-    assert result.body["value"] is None
+    assert_success(result)
 
     result = session.transport.send("GET", "session/%s/cookie" % session.session_id)
     assert result.status == 200
     assert "value" in result.body
     assert isinstance(result.body["value"], list)
     assert len(result.body["value"]) == 1
     assert isinstance(result.body["value"][0], dict)
 
@@ -31,36 +30,35 @@ def test_add_domain_cookie(session, url,
     assert isinstance(cookie["name"], basestring)
     assert "value" in cookie
     assert isinstance(cookie["value"], basestring)
     assert "domain" in cookie
     assert isinstance(cookie["domain"], basestring)
 
     assert cookie["name"] == "hello"
     assert cookie["value"] == "world"
-    assert cookie["domain"] == ".%s" % server_config["domains"][""] or cookie["domain"] == "%s" % server_config["domains"][""]
+    assert cookie["domain"] == server_config["browser_host"] or \
+        cookie["domain"] == ".%s" % server_config["browser_host"]
 
 def test_add_cookie_for_ip(session, url, server_config, configuration):
     session.url = "http://127.0.0.1:%s/common/blank.html" % (server_config["ports"]["http"][0])
     clear_all_cookies(session)
     create_cookie_request = {
         "cookie": {
             "name": "hello",
             "value": "world",
             "domain": "127.0.0.1",
             "path": "/",
             "httpOnly": False,
             "secure": False
         }
     }
 
     result = session.transport.send("POST", "session/%s/cookie" % session.session_id, create_cookie_request)
-    assert result.status == 200
-    assert "value" in result.body
-    assert result.body["value"] is None
+    assert_success(result)
 
     result = session.transport.send("GET", "session/%s/cookie" % session.session_id)
     assert result.status == 200
     assert "value" in result.body
     assert isinstance(result.body["value"], list)
     assert len(result.body["value"]) == 1
     assert isinstance(result.body["value"][0], dict)
 
@@ -83,19 +81,17 @@ def test_add_non_session_cookie(session,
     create_cookie_request = {
         "cookie": {
             "name": "hello",
             "value": "world",
             "expiry": a_year_from_now
         }
     }
     result = session.transport.send("POST", "session/%s/cookie" % session.session_id, create_cookie_request)
-    assert result.status == 200
-    assert "value" in result.body
-    assert result.body["value"] is None
+    assert_success(result)
 
     result = session.transport.send("GET", "session/%s/cookie" % session.session_id)
     assert result.status == 200
     assert "value" in result.body
     assert isinstance(result.body["value"], list)
     assert len(result.body["value"]) == 1
     assert isinstance(result.body["value"][0], dict)
 
@@ -116,19 +112,17 @@ def test_add_session_cookie(session, url
     clear_all_cookies(session)
     create_cookie_request = {
         "cookie": {
             "name": "hello",
             "value": "world"
         }
     }
     result = session.transport.send("POST", "session/%s/cookie" % session.session_id, create_cookie_request)
-    assert result.status == 200
-    assert "value" in result.body
-    assert result.body["value"] is None
+    assert_success(result)
 
     result = session.transport.send("GET", "session/%s/cookie" % session.session_id)
     assert result.status == 200
     assert "value" in result.body
     assert isinstance(result.body["value"], list)
     assert len(result.body["value"]) == 1
     assert isinstance(result.body["value"][0], dict)
 
@@ -145,23 +139,21 @@ def test_add_session_cookie(session, url
 
 def test_add_session_cookie_with_leading_dot_character_in_domain(session, url, server_config):
     session.url = url("/common/blank.html")
     clear_all_cookies(session)
     create_cookie_request = {
         "cookie": {
             "name": "hello",
             "value": "world",
-            "domain": ".%s" % server_config["domains"][""]
+            "domain": ".%s" % server_config["browser_host"]
         }
     }
     result = session.transport.send("POST", "session/%s/cookie" % session.session_id, create_cookie_request)
-    assert result.status == 200
-    assert "value" in result.body
-    assert result.body["value"] is None
+    assert_success(result)
 
     result = session.transport.send("GET", "session/%s/cookie" % session.session_id)
     assert result.status == 200
     assert "value" in result.body
     assert isinstance(result.body["value"], list)
     assert len(result.body["value"]) == 1
     assert isinstance(result.body["value"][0], dict)
 
@@ -170,9 +162,10 @@ def test_add_session_cookie_with_leading
     assert isinstance(cookie["name"], basestring)
     assert "value" in cookie
     assert isinstance(cookie["value"], basestring)
     assert "domain" in cookie
     assert isinstance(cookie["domain"], basestring)
 
     assert cookie["name"] == "hello"
     assert cookie["value"] == "world"
-    assert cookie["domain"] == ".%s" % server_config["domains"][""] or cookie["domain"] == "%s" % server_config["domains"][""]
+    assert cookie["domain"] == server_config["browser_host"] or \
+        cookie["domain"] == ".%s" % server_config["browser_host"]