--- a/testing/web-platform/meta/MANIFEST.json
+++ b/testing/web-platform/meta/MANIFEST.json
@@ -523104,17 +523104,17 @@
    "ab3c3d205e59df800ba5b4217245b83685521c31",
    "reftest"
   ],
   "css/css-scoping/shadow-host-with-before-after.html": [
    "99af6e29e69b3131b59dbdc2b0eead52931123c2",
    "reftest"
   ],
   "css/css-scoping/shadow-link-rel-stylesheet-no-style-leak.html": [
-   "76a54dabd8bd09f7155ab0331e3d17d1a0cae243",
+   "a46be006762a16c2deb3d1d3a760e3c4e348668c",
    "reftest"
   ],
   "css/css-scoping/shadow-link-rel-stylesheet.html": [
    "07862ce7d2a954988bdbce882869a4c5f097089a",
    "reftest"
   ],
   "css/css-scoping/shadow-reassign-dynamic-001.html": [
    "11ed4da2e6ce88d8a2b98a8f1c814417ef7770dd",
@@ -559700,17 +559700,17 @@
    "d1661ab1734f7d1a252030aeac7e9842a7a4cb3b",
    "testharness"
   ],
   "custom-elements/Document-createElement-svg.svg": [
    "9af8f2dc7778feeea4fa8e557d7885b10d325dea",
    "testharness"
   ],
   "custom-elements/Document-createElement.html": [
-   "46e64c9f412fb04582f8ec287e08783ac83cb933",
+   "0edab8da0f16d5d2239ffb21f446c371fe4c76c3",
    "testharness"
   ],
   "custom-elements/Document-createElementNS.html": [
    "da90b2a1c13cf18fd5cade85dcae2dadef6243c9",
    "testharness"
   ],
   "custom-elements/HTMLElement-constructor.html": [
    "4dc04a8b026538bddee52586f2df50206abc9334",
@@ -577844,17 +577844,17 @@
    "da39a3ee5e6b4b0d3255bfef95601890afd80709",
    "support"
   ],
   "html/resources/common.js": [
    "0f18ee2c61b99893cfe2a3d1ff549b170a8d715d",
    "support"
   ],
   "html/scripting/the-noscript-element/non-html-noscript.html": [
-   "c0c5453111f29e5a0206f988f4d127ec8ebc2f13",
+   "121760184777008c2ddeb598278216e40b34e367",
    "testharness"
   ],
   "html/semantics/.gitkeep": [
    "da39a3ee5e6b4b0d3255bfef95601890afd80709",
    "support"
   ],
   "html/semantics/OWNERS": [
    "abd95839027a88741c4d351ff374d81b773c80fa",
@@ -609796,17 +609796,17 @@
    "9bea44e9ab6d8452aadc57d5e6d5a1eaa017ac78",
    "support"
   ],
   "service-workers/service-worker/resources/pass.txt": [
    "27d2303f215d7d1a8f12f0b80b9b56a2cdf6c9a7",
    "support"
   ],
   "service-workers/service-worker/resources/performance-timeline-worker.js": [
-   "fc275abc58d82c338ff369ba62994bd3d5609a67",
+   "c4c32d5b7ca352a3f18548928570a8a7339fa687",
    "support"
   ],
   "service-workers/service-worker/resources/postmessage-blob-url.js": [
    "728244e7f0b717aec29c3057bde7a6ba12768587",
    "support"
   ],
   "service-workers/service-worker/resources/postmessage-msgport-to-client-worker.js": [
    "11d46afb4cf17c8dcd9b49cda4e07e110a42a36d",

--- a/testing/web-platform/tests/tools/webdriver/webdriver/__init__.py
+++ b/testing/web-platform/tests/tools/webdriver/webdriver/__init__.py
@@ -1,9 +1,16 @@
-from client import Cookies, Element, Find, Session, Timeouts, Window
+from client import (
+    Cookies,
+    Element,
+    Find,
+    Frame,
+    Session,
+    Timeouts,
+    Window)
 from error import (
     ElementNotSelectableException,
     ElementNotVisibleException,
     InvalidArgumentException,
     InvalidCookieDomainException,
     InvalidElementCoordinatesException,
     InvalidElementStateException,
     InvalidSelectorException,

--- a/testing/web-platform/tests/tools/webdriver/webdriver/client.py
+++ b/testing/web-platform/tests/tools/webdriver/webdriver/client.py
@@ -229,16 +229,18 @@ class Actions(object):
         """Return an empty ActionSequence of the designated type.
 
         See ActionSequence for parameter list.
         """
         return ActionSequence(self.session, *args, **kwargs)
 
 
 class Window(object):
+    identifier = "window-fcc6-11e5-b4f8-330a88ab9d7f"
+
     def __init__(self, session):
         self.session = session
 
     @property
     @command
     def rect(self):
         return self.session.send_session_command("GET", "window/rect")
 
@@ -279,16 +281,33 @@ class Window(object):
     @command
     def minimize(self):
         return self.session.send_session_command("POST", "window/minimize")
 
     @command
     def fullscreen(self):
         return self.session.send_session_command("POST", "window/fullscreen")
 
+    @classmethod
+    def from_json(cls, json, session):
+        uuid = json[Window.identifier]
+        return cls(uuid, session)
+
+
+class Frame(object):
+    identifier = "frame-075b-4da1-b6ba-e579c2d3230a"
+
+    def __init__(self, session):
+        self.session = session
+
+    @classmethod
+    def from_json(cls, json, session):
+        uuid = json[Frame.identifier]
+        return cls(uuid, session)
+
 
 class Find(object):
     def __init__(self, session):
         self.session = session
 
     @command
     def css(self, selector, all=True):
         return self._find_element("css selector", selector, all)

--- a/testing/web-platform/tests/tools/webdriver/webdriver/protocol.py
+++ b/testing/web-platform/tests/tools/webdriver/webdriver/protocol.py
@@ -11,25 +11,33 @@ class Encoder(json.JSONEncoder):
         kwargs.pop("session")
         super(Encoder, self).__init__(*args, **kwargs)
 
     def default(self, obj):
         if isinstance(obj, (list, tuple)):
             return [self.default(x) for x in obj]
         elif isinstance(obj, webdriver.Element):
             return {webdriver.Element.identifier: obj.id}
+        elif isinstance(obj, webdriver.Frame):
+            return {webdriver.Frame.identifier: obj.id}
+        elif isinstance(obj, webdriver.Window):
+            return {webdriver.Frame.identifier: obj.id}
         return super(Encoder, self).default(obj)
 
 
 class Decoder(json.JSONDecoder):
     def __init__(self, *args, **kwargs):
         self.session = kwargs.pop("session")
         super(Decoder, self).__init__(
             object_hook=self.object_hook, *args, **kwargs)
 
     def object_hook(self, payload):
         if isinstance(payload, (list, tuple)):
             return [self.object_hook(x) for x in payload]
         elif isinstance(payload, dict) and webdriver.Element.identifier in payload:
             return webdriver.Element.from_json(payload, self.session)
+        elif isinstance(payload, dict) and webdriver.Frame.identifier in payload:
+            return webdriver.Frame.from_json(payload, self.session)
+        elif isinstance(payload, dict) and webdriver.Window.identifier in payload:
+            return webdriver.Window.from_json(payload, self.session)
         elif isinstance(payload, dict):
             return {k: self.object_hook(v) for k, v in payload.iteritems()}
         return payload

--- a/testing/web-platform/tests/tools/webdriver/webdriver/transport.py
+++ b/testing/web-platform/tests/tools/webdriver/webdriver/transport.py
@@ -45,18 +45,19 @@ class Response(object):
         return cls(http_response.status, body)
 
 
 class HTTPWireProtocol(object):
     """
     Transports messages (commands and responses) over the WebDriver
     wire protocol.
 
-    Complex objects, such as ``webdriver.Element``, are by default
-    not marshaled to enable use of `session.transport.send` in WPT tests::
+    Complex objects, such as ``webdriver.Element``, ``webdriver.Frame``,
+    and ``webdriver.Window`` are by default not marshaled to enable
+    use of `session.transport.send` in WPT tests::
 
         session = webdriver.Session("127.0.0.1", 4444)
         response = transport.send("GET", "element/active", None)
         print response.body["value"]
         # => {u'element-6066-11e4-a52e-4f735466cecf': u'<uuid>'}
 
     Automatic marshaling is provided by ``webdriver.protocol.Encoder``
     and ``webdriver.protocol.Decoder``, which can be passed in to
@@ -95,18 +96,19 @@ class HTTPWireProtocol(object):
              encoder=json.JSONEncoder,
              decoder=json.JSONDecoder,
              **codec_kwargs):
         """
         Send a command to the remote.
 
         The request `body` must be JSON serialisable unless a
         custom `encoder` has been provided.  This means complex
-        objects such as ``webdriver.Element`` are not automatically
-        made into JSON.  This behaviour is, however, provided by
+        objects such as ``webdriver.Element``, ``webdriver.Frame``,
+        and `webdriver.Window`` are not automatically made
+        into JSON.  This behaviour is, however, provided by
         ``webdriver.protocol.Encoder``, should you want it.
 
         Similarly, the response body is returned au natural
         as plain JSON unless a `decoder` that converts web
         element references to ``webdriver.Element`` is provided.
         Use ``webdriver.protocol.Decoder`` to achieve this behaviour.
 
         :param method: `GET`, `POST`, or `DELETE`.