--- a/dom/webidl/Client.webidl
+++ b/dom/webidl/Client.webidl
@@ -1,38 +1,49 @@
 /* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this file,
  * You can obtain one at http://mozilla.org/MPL/2.0/.
  *
  * The origin of this IDL file is
- * http://slightlyoff.github.io/ServiceWorker/spec/service_worker/index.html
+ * https://w3c.github.io/ServiceWorker/#client-interface
  *
  */
 
 [Exposed=ServiceWorker]
 interface Client {
   readonly attribute USVString url;
+
+  // Remove frameType in bug 1290936
   readonly attribute FrameType frameType;
+
+  readonly attribute ClientType type;
   readonly attribute DOMString id;
 
+  // Implement reserved in bug 1264177
+  // readonly attribute boolean reserved;
+
   [Throws]
   void postMessage(any message, optional sequence<object> transfer = []);
 };
 
 [Exposed=ServiceWorker]
 interface WindowClient : Client {
   readonly attribute VisibilityState visibilityState;
   readonly attribute boolean focused;
 
+  // Implement ancestorOrigins in bug 1264180
+  // [SameObject] readonly attribute FrozenArray<USVString> ancestorOrigins;
+
   [Throws, NewObject]
   Promise<WindowClient> focus();
 
   [Throws, NewObject]
   Promise<WindowClient> navigate(USVString url);
 };
 
+// Remove FrameType in bug 1290936
 enum FrameType {
   "auxiliary",
   "top-level",
   "nested",
   "none"
 };

--- a/dom/workers/ServiceWorkerClient.cpp
+++ b/dom/workers/ServiceWorkerClient.cpp
@@ -29,17 +29,18 @@ NS_IMPL_CYCLE_COLLECTING_ADDREF(ServiceW
 NS_IMPL_CYCLE_COLLECTING_RELEASE(ServiceWorkerClient)
 
 NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(ServiceWorkerClient)
   NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY
   NS_INTERFACE_MAP_ENTRY(nsISupports)
 NS_INTERFACE_MAP_END
 
 ServiceWorkerClientInfo::ServiceWorkerClientInfo(nsIDocument* aDoc)
-  : mWindowId(0)
+  : mType(ClientType::Window)
+  , mWindowId(0)
   , mFrameType(FrameType::None)
 {
   MOZ_ASSERT(aDoc);
   nsresult rv = aDoc->GetOrCreateId(mClientId);
   if (NS_FAILED(rv)) {
     NS_WARNING("Failed to get the UUID of the document.");
   }
 
@@ -77,16 +78,22 @@ ServiceWorkerClientInfo::ServiceWorkerCl
 }
 
 JSObject*
 ServiceWorkerClient::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto)
 {
   return ClientBinding::Wrap(aCx, this, aGivenProto);
 }
 
+ClientType
+ServiceWorkerClient::Type() const
+{
+  return mType;
+}
+
 namespace {
 
 class ServiceWorkerClientPostMessageRunnable final
   : public Runnable
   , public StructuredCloneHolder
 {
   uint64_t mWindowId;
 

--- a/dom/workers/ServiceWorkerClient.h
+++ b/dom/workers/ServiceWorkerClient.h
@@ -34,16 +34,17 @@ public:
   explicit ServiceWorkerClientInfo(nsIDocument* aDoc);
 
   const nsString& ClientId() const
   {
     return mClientId;
   }
 
 private:
+  const mozilla::dom::ClientType mType;
   nsString mClientId;
   uint64_t mWindowId;
   nsString mUrl;
 
   // Window Clients
   VisibilityState mVisibilityState;
   bool mFocused;
   FrameType mFrameType;
@@ -54,16 +55,17 @@ class ServiceWorkerClient : public nsISu
 {
 public:
   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
   NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(ServiceWorkerClient)
 
   ServiceWorkerClient(nsISupports* aOwner,
                       const ServiceWorkerClientInfo& aClientInfo)
     : mOwner(aOwner)
+    , mType(aClientInfo.mType)
     , mId(aClientInfo.mClientId)
     , mUrl(aClientInfo.mUrl)
     , mWindowId(aClientInfo.mWindowId)
     , mFrameType(aClientInfo.mFrameType)
   {
     MOZ_ASSERT(aOwner);
   }
 
@@ -85,28 +87,32 @@ public:
   }
 
   mozilla::dom::FrameType
   FrameType() const
   {
     return mFrameType;
   }
 
+  mozilla::dom::ClientType
+  Type() const;
+
   void
   PostMessage(JSContext* aCx, JS::Handle<JS::Value> aMessage,
               const Sequence<JSObject*>& aTransferable, ErrorResult& aRv);
 
   JSObject* WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) override;
 
 protected:
   virtual ~ServiceWorkerClient()
   { }
 
 private:
   nsCOMPtr<nsISupports> mOwner;
+  const ClientType mType;
   nsString mId;
   nsString mUrl;
 
 protected:
   uint64_t mWindowId;
   mozilla::dom::FrameType mFrameType;
 };