--- a/dom/base/nsGlobalWindow.cpp
+++ b/dom/base/nsGlobalWindow.cpp
@@ -82,17 +82,16 @@
 #include "nsIDocument.h"
 #include "Crypto.h"
 #ifndef MOZ_DISABLE_CRYPTOLEGACY
 #include "nsIDOMCryptoLegacy.h"
 #endif
 #include "nsIDOMDocument.h"
 #include "nsIDOMElement.h"
 #include "nsIDOMEvent.h"
-#include "nsIDOMPopStateEvent.h"
 #include "nsIDOMOfflineResourceList.h"
 #include "nsPIDOMStorage.h"
 #include "nsDOMString.h"
 #include "nsIEmbeddingSiteWindow.h"
 #include "nsThreadUtils.h"
 #include "nsILoadContext.h"
 #include "nsIMarkupDocumentViewer.h"
 #include "nsIPresShell.h"
@@ -211,16 +210,17 @@
 #include "prrng.h"
 #include "nsSandboxFlags.h"
 #include "TimeChangeObserver.h"
 #include "mozilla/dom/AudioContext.h"
 #include "mozilla/dom/BrowserElementDictionariesBinding.h"
 #include "mozilla/dom/Console.h"
 #include "mozilla/dom/FunctionBinding.h"
 #include "mozilla/dom/HashChangeEvent.h"
+#include "mozilla/dom/PopStateEvent.h"
 #include "mozilla/dom/PopupBlockedEvent.h"
 #include "mozilla/dom/WindowBinding.h"
 #include "nsITabChild.h"
 #include "mozilla/dom/MediaQueryList.h"
 #include "mozilla/dom/ScriptSettings.h"
 #include "mozilla/dom/NavigatorBinding.h"
 #ifdef HAVE_SIDEBAR
 #include "mozilla/dom/ExternalBinding.h"
@@ -10152,41 +10152,43 @@ nsGlobalWindow::DispatchSyncPopState()
 
   // Obtain a presentation shell for use in creating a popstate event.
   nsIPresShell *shell = mDoc->GetShell();
   nsRefPtr<nsPresContext> presContext;
   if (shell) {
     presContext = shell->GetPresContext();
   }
 
-  // Create a new popstate event
-  nsCOMPtr<nsIDOMEvent> domEvent;
-  rv = EventDispatcher::CreateEvent(this, presContext, nullptr,
-                                    NS_LITERAL_STRING("popstateevent"),
-                                    getter_AddRefs(domEvent));
-  NS_ENSURE_SUCCESS(rv, rv);
-
-  // Initialize the popstate event, which does bubble but isn't cancellable.
-  nsCOMPtr<nsIDOMPopStateEvent> popstateEvent = do_QueryInterface(domEvent);
-  rv = popstateEvent->InitPopStateEvent(NS_LITERAL_STRING("popstate"),
-                                        true, false,
-                                        stateObj);
-  NS_ENSURE_SUCCESS(rv, rv);
-
-  domEvent->SetTrusted(true);
-
-  nsCOMPtr<EventTarget> outerWindow =
-    do_QueryInterface(GetOuterWindow());
-  NS_ENSURE_TRUE(outerWindow, NS_ERROR_UNEXPECTED);
-
-  rv = domEvent->SetTarget(outerWindow);
-  NS_ENSURE_SUCCESS(rv, rv);
+  bool result = true;
+  nsPIDOMWindow* outerWindow = GetOuterWindow();
+  nsCOMPtr<EventTarget> outerWindowET = do_QueryInterface(outerWindow);
+  NS_ENSURE_TRUE(outerWindowET, NS_ERROR_FAILURE);
+
+  AutoJSAPI jsapi;
+  result = jsapi.Init(outerWindow);
+  NS_ENSURE_TRUE(result, NS_ERROR_FAILURE);
+
+  JSContext* cx = jsapi.cx();
+  JS::Rooted<JS::Value> stateJSValue(cx, JS::NullValue());
+  result = stateObj ? VariantToJsval(cx, stateObj, &stateJSValue) : true;
+  NS_ENSURE_TRUE(result, NS_ERROR_FAILURE);
+
+  RootedDictionary<PopStateEventInit> init(cx);
+  init.mBubbles = true;
+  init.mCancelable = false;
+  init.mState = stateJSValue;
+
+  nsRefPtr<PopStateEvent> event =
+    PopStateEvent::Constructor(outerWindowET, NS_LITERAL_STRING("popstate"),
+                               init);
+  event->SetTrusted(true);
+  event->SetTarget(outerWindowET);
 
   bool dummy; // default action
-  return DispatchEvent(popstateEvent, &dummy);
+  return DispatchEvent(event, &dummy);
 }
 
 // Find an nsICanvasFrame under aFrame.  Only search the principal
 // child lists.  aFrame must be non-null.
 static nsCanvasFrame* FindCanvasFrame(nsIFrame* aFrame)
 {
     nsCanvasFrame* canvasFrame = do_QueryFrame(aFrame);
     if (canvasFrame) {

--- a/dom/events/EventDispatcher.cpp
+++ b/dom/events/EventDispatcher.cpp
@@ -13,16 +13,17 @@
 #include "nsINode.h"
 #include "nsPIDOMWindow.h"
 #include "GeckoProfiler.h"
 #include "GeneratedEvents.h"
 #include "mozilla/ContentEvents.h"
 #include "mozilla/dom/CloseEvent.h"
 #include "mozilla/dom/EventTarget.h"
 #include "mozilla/dom/HashChangeEvent.h"
+#include "mozilla/dom/PopStateEvent.h"
 #include "mozilla/dom/StorageEvent.h"
 #include "mozilla/dom/TouchEvent.h"
 #include "mozilla/EventDispatcher.h"
 #include "mozilla/EventListenerManager.h"
 #include "mozilla/InternalMutationEvent.h"
 #include "mozilla/MiscEvents.h"
 #include "mozilla/MouseEvents.h"
 #include "mozilla/TextEvents.h"
@@ -813,25 +814,34 @@ EventDispatcher::CreateEvent(EventTarget
   if (aEventType.LowerCaseEqualsLiteral("beforeunloadevent"))
     return NS_NewDOMBeforeUnloadEvent(aDOMEvent, aOwner, aPresContext, nullptr);
   if (aEventType.LowerCaseEqualsLiteral("pagetransition"))
     return NS_NewDOMPageTransitionEvent(aDOMEvent, aOwner, aPresContext, nullptr);
   if (aEventType.LowerCaseEqualsLiteral("domtransaction"))
     return NS_NewDOMDOMTransactionEvent(aDOMEvent, aOwner, aPresContext, nullptr);
   if (aEventType.LowerCaseEqualsLiteral("scrollareaevent"))
     return NS_NewDOMScrollAreaEvent(aDOMEvent, aOwner, aPresContext, nullptr);
-  if (aEventType.LowerCaseEqualsLiteral("popstateevent"))
-    return NS_NewDOMPopStateEvent(aDOMEvent, aOwner, aPresContext, nullptr);
   if (aEventType.LowerCaseEqualsLiteral("closeevent")) {
     CloseEventInit init;
     nsRefPtr<CloseEvent> event =
       CloseEvent::Constructor(aOwner, EmptyString(), init);
     event.forget(aDOMEvent);
     return NS_OK;
   }
+  // XXXkhuey Chrome supports popstateevent here, even though it provides no
+  // initPopStateEvent method.  This is nuts ... but copying it is unlikely to
+  // break the web.
+  if (aEventType.LowerCaseEqualsLiteral("popstateevent")) {
+    AutoJSContext cx;
+    RootedDictionary<PopStateEventInit> init(cx);
+    nsRefPtr<PopStateEvent> event =
+      PopStateEvent::Constructor(aOwner, EmptyString(), init);
+    event.forget(aDOMEvent);
+    return NS_OK;
+  }
   if (aEventType.LowerCaseEqualsLiteral("touchevent") &&
       TouchEvent::PrefEnabled())
     return NS_NewDOMTouchEvent(aDOMEvent, aOwner, aPresContext, nullptr);
   if (aEventType.LowerCaseEqualsLiteral("hashchangeevent")) {
     HashChangeEventInit init;
     nsRefPtr<HashChangeEvent> event =
       HashChangeEvent::Constructor(aOwner, EmptyString(), init);
     event.forget(aDOMEvent);

--- a/dom/interfaces/events/moz.build
+++ b/dom/interfaces/events/moz.build
@@ -24,17 +24,16 @@ XPIDL_SOURCES += [
     'nsIDOMMessageEvent.idl',
     'nsIDOMMouseEvent.idl',
     'nsIDOMMouseScrollEvent.idl',
     'nsIDOMMutationEvent.idl',
     'nsIDOMNotifyPaintEvent.idl',
     'nsIDOMNSEvent.idl',
     'nsIDOMPageTransitionEvent.idl',
     'nsIDOMPaintRequest.idl',
-    'nsIDOMPopStateEvent.idl',
     'nsIDOMRecordErrorEvent.idl',
     'nsIDOMScrollAreaEvent.idl',
     'nsIDOMSimpleGestureEvent.idl',
     'nsIDOMSmartCardEvent.idl',
     'nsIDOMStyleRuleChangeEvent.idl',
     'nsIDOMStyleSheetApplicableStateChangeEvent.idl',
     'nsIDOMStyleSheetChangeEvent.idl',
     'nsIDOMTouchEvent.idl',

deleted file mode 100644
--- a/dom/interfaces/events/nsIDOMPopStateEvent.idl
+++ /dev/null
@@ -1,22 +0,0 @@
-/* -*- Mode: C++; 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/. */
-
-#include "nsIDOMEvent.idl"
-
-interface nsIVariant;
-
-[builtinclass, uuid(f0def4a3-0eb3-4c08-b476-582e37b8564b)]
-interface nsIDOMPopStateEvent : nsIDOMEvent
-{
-  /**
-   * The state associated with this popstate event
-   */
-  readonly attribute nsIVariant state;
-
-  void initPopStateEvent(in DOMString typeArg,
-                         in boolean canBubbleArg,
-                         in boolean cancelableArg,
-                         in nsIVariant stateArg);
-};

--- a/dom/tests/mochitest/general/test_bug653364.html
+++ b/dom/tests/mochitest/general/test_bug653364.html
@@ -23,16 +23,17 @@ https://bugzilla.mozilla.org/show_bug.cg
 
 gotPopState = 0;
 document.addEventListener("popState", function(e) {
   gotPopState = 1;
   is(e.state.foo, 'bar', "PopState event should have state we set.");
   is(e.isTrusted, false, "PopState event shouldn't be trusted.");
 }, true);
 
-let ps = document.createEvent("PopStateEvent");
-ps.initPopStateEvent("popState", true, false, {'foo': 'bar'});
+let ps = new PopStateEvent("popState", { bubbles: true,
+                                         cancelable: false,
+                                         state: {'foo': 'bar'} });
 document.documentElement.dispatchEvent(ps);
 is(gotPopState, 1, 'Document received PopState event.');
 
 </script>
 </body>
 </html>

--- a/dom/webidl/PopStateEvent.webidl
+++ b/dom/webidl/PopStateEvent.webidl
@@ -1,24 +1,16 @@
 /* -*- 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/.
  */
 
-[Constructor(DOMString type, optional PopStateEventInit eventInitDict), HeaderFile="GeneratedEventClasses.h"]
+[Constructor(DOMString type, optional PopStateEventInit eventInitDict)]
 interface PopStateEvent : Event
 {
-  [Throws]
   readonly attribute any state;
-
-  // initPopStateEvent is a Gecko specific deprecated method.
-  [Throws]
-  void initPopStateEvent(DOMString type,
-                         boolean canBubble,
-                         boolean cancelable,
-                         any state);
 };
 
 dictionary PopStateEventInit : EventInit
 {
   any state = null;
 };

--- a/dom/webidl/moz.build
+++ b/dom/webidl/moz.build
@@ -642,16 +642,17 @@ GENERATED_EVENTS_WEBIDL_FILES = [
     'MozClirModeEvent.webidl',
     'MozContactChangeEvent.webidl',
     'MozEmergencyCbModeEvent.webidl',
     'MozInterAppMessageEvent.webidl',
     'MozMmsEvent.webidl',
     'MozOtaStatusEvent.webidl',
     'MozSmsEvent.webidl',
     'MozStkCommandEvent.webidl',
+    'PopStateEvent.webidl',
     'PopupBlockedEvent.webidl',
     'ProgressEvent.webidl',
     'RTCDataChannelEvent.webidl',
     'RTCPeerConnectionIceEvent.webidl',
     'RTCPeerConnectionIdentityErrorEvent.webidl',
     'RTCPeerConnectionIdentityEvent.webidl',
     'TrackEvent.webidl',
     'UserProximityEvent.webidl',

--- a/js/xpconnect/src/event_impl_gen.conf.in
+++ b/js/xpconnect/src/event_impl_gen.conf.in
@@ -7,17 +7,16 @@
  and should be in nsIDOM<name>.idl file and which should have
  <name>Init dictionary for the event constructor. """
 
 simple_events = [
     'MozSettingsEvent',
     'CustomEvent',
     'PageTransitionEvent',
     'DOMTransactionEvent',
-    'PopStateEvent',
     'DeviceOrientationEvent',
     'MozApplicationEvent',
     'SmartCardEvent',
     'StyleRuleChangeEvent',
     'StyleSheetChangeEvent',
     'StyleSheetApplicableStateChangeEvent',
 #ifdef MOZ_WEBSPEECH
     'SpeechSynthesisEvent',

--- a/xpcom/reflect/xptinfo/ShimInterfaceInfo.cpp
+++ b/xpcom/reflect/xptinfo/ShimInterfaceInfo.cpp
@@ -118,17 +118,16 @@
 #include "nsIDOMNode.h"
 #include "nsIDOMNodeIterator.h"
 #include "nsIDOMNotifyPaintEvent.h"
 #include "nsIDOMNSEvent.h"
 #include "nsIDOMOfflineResourceList.h"
 #include "nsIDOMPageTransitionEvent.h"
 #include "nsIDOMPaintRequest.h"
 #include "nsIDOMParser.h"
-#include "nsIDOMPopStateEvent.h"
 #include "nsIDOMProcessingInstruction.h"
 #include "nsIDOMRange.h"
 #include "nsIDOMRecordErrorEvent.h"
 #include "nsIDOMRect.h"
 #include "nsIDOMScreen.h"
 #include "nsIDOMScrollAreaEvent.h"
 #include "nsIDOMSerializer.h"
 #include "nsIDOMSimpleGestureEvent.h"
@@ -273,17 +272,16 @@
 #include "mozilla/dom/MozSettingsEventBinding.h"
 #include "mozilla/dom/NodeIteratorBinding.h"
 #include "mozilla/dom/NodeBinding.h"
 #include "mozilla/dom/NotifyPaintEventBinding.h"
 #include "mozilla/dom/EventBinding.h"
 #include "mozilla/dom/OfflineResourceListBinding.h"
 #include "mozilla/dom/PageTransitionEventBinding.h"
 #include "mozilla/dom/PaintRequestBinding.h"
-#include "mozilla/dom/PopStateEventBinding.h"
 #include "mozilla/dom/PositionErrorBinding.h"
 #include "mozilla/dom/ProcessingInstructionBinding.h"
 #include "mozilla/dom/RangeBinding.h"
 #include "mozilla/dom/RecordErrorEventBinding.h"
 #include "mozilla/dom/RectBinding.h"
 #include "mozilla/dom/ScreenBinding.h"
 #include "mozilla/dom/SelectionBinding.h"
 #include "mozilla/dom/ScrollAreaEventBinding.h"
@@ -481,17 +479,16 @@ const ComponentsInterfaceShimEntry kComp
   DEFINE_SHIM(NodeIterator),
   DEFINE_SHIM(Node),
   DEFINE_SHIM(NotifyPaintEvent),
   DEFINE_SHIM_WITH_CUSTOM_INTERFACE(nsIDOMNSEvent, Event),
   DEFINE_SHIM(OfflineResourceList),
   DEFINE_SHIM(PageTransitionEvent),
   DEFINE_SHIM(PaintRequest),
   DEFINE_SHIM_WITH_CUSTOM_INTERFACE(nsIDOMParser, DOMParser),
-  DEFINE_SHIM(PopStateEvent),
   DEFINE_SHIM(ProcessingInstruction),
   DEFINE_SHIM(Range),
   DEFINE_SHIM(RecordErrorEvent),
   DEFINE_SHIM(Rect),
   DEFINE_SHIM(Screen),
   DEFINE_SHIM(ScrollAreaEvent),
   DEFINE_SHIM_WITH_CUSTOM_INTERFACE(nsIDOMSerializer, XMLSerializer),
   DEFINE_SHIM(SimpleGestureEvent),