--- a/testing/cppunittest.ini
+++ b/testing/cppunittest.ini
@@ -1,11 +1,10 @@
 [ShowSSEConfig]
 [TestPrintf]
-[TestAppShellSteadyState]
 [TestAlgorithm]
 [TestArray]
 [TestArrayUtils]
 [TestAtomics]
 [TestBinarySearch]
 [TestBloomFilter]
 [TestBufferList]
 [TestCasting]

deleted file mode 100644
--- a/widget/tests/TestAppShellSteadyState.cpp
+++ /dev/null
@@ -1,450 +0,0 @@
-/**
- * Any copyright is dedicated to the Public Domain.
- * http://creativecommons.org/publicdomain/zero/1.0/
- */
-
-#include "TestHarness.h"
-
-#include "nsGlobalWindowOuter.h"
-#include "nsIAppShell.h"
-#include "nsIAppShellService.h"
-#include "mozilla/dom/Document.h"
-#include "nsIDOMEventListener.h"
-#include "nsIDOMWindow.h"
-#include "nsIDOMWindowUtils.h"
-#include "nsIInterfaceRequestor.h"
-#include "nsIRunnable.h"
-#include "nsIURI.h"
-#include "nsIWebBrowserChrome.h"
-#include "nsIAppWindow.h"
-
-#include "nsAppShellCID.h"
-#include "nsIInterfaceRequestorUtils.h"
-#include "nsNetUtil.h"
-#include "nsThreadUtils.h"
-#include "mozilla/Attributes.h"
-#include "mozilla/dom/Event.h"
-#include "mozilla/dom/EventTarget.h"
-
-#ifdef XP_WIN
-#  include <windows.h>
-#endif
-
-using namespace mozilla;
-
-typedef void (*TestFunc)(nsIAppShell*);
-
-bool gStableStateEventHasRun = false;
-
-class ExitAppShellRunnable : public Runnable {
-  nsCOMPtr<nsIAppShell> mAppShell;
-
- public:
-  explicit ExitAppShellRunnable(nsIAppShell* aAppShell)
-      : mAppShell(aAppShell) {}
-
-  NS_IMETHOD
-  Run() override { return mAppShell->Exit(); }
-};
-
-class StableStateRunnable : public Runnable {
- public:
-  NS_IMETHOD
-  Run() override {
-    if (gStableStateEventHasRun) {
-      fail("StableStateRunnable already ran");
-    }
-    gStableStateEventHasRun = true;
-    return NS_OK;
-  }
-};
-
-class CheckStableStateRunnable : public Runnable {
-  bool mShouldHaveRun;
-
- public:
-  explicit CheckStableStateRunnable(bool aShouldHaveRun)
-      : mShouldHaveRun(aShouldHaveRun) {}
-
-  NS_IMETHOD
-  Run() override {
-    if (mShouldHaveRun == gStableStateEventHasRun) {
-      passed("StableStateRunnable state correct (%s)",
-             mShouldHaveRun ? "true" : "false");
-    } else {
-      fail("StableStateRunnable ran at wrong time");
-    }
-    return NS_OK;
-  }
-};
-
-class ScheduleStableStateRunnable : public CheckStableStateRunnable {
- protected:
-  nsCOMPtr<nsIAppShell> mAppShell;
-
- public:
-  explicit ScheduleStableStateRunnable(nsIAppShell* aAppShell)
-      : CheckStableStateRunnable(false), mAppShell(aAppShell) {}
-
-  NS_IMETHOD
-  Run() override {
-    CheckStableStateRunnable::Run();
-
-    nsCOMPtr<nsIRunnable> runnable = new StableStateRunnable();
-    nsresult rv = mAppShell->RunBeforeNextEvent(runnable);
-    if (NS_FAILED(rv)) {
-      fail("RunBeforeNextEvent returned failure code %u", rv);
-    }
-
-    return rv;
-  }
-};
-
-class NextTestRunnable : public Runnable {
-  nsCOMPtr<nsIAppShell> mAppShell;
-
- public:
-  explicit NextTestRunnable(nsIAppShell* aAppShell) : mAppShell(aAppShell) {}
-
-  NS_IMETHOD Run() override;
-};
-
-class ScheduleNestedStableStateRunnable : public ScheduleStableStateRunnable {
- public:
-  explicit ScheduleNestedStableStateRunnable(nsIAppShell* aAppShell)
-      : ScheduleStableStateRunnable(aAppShell) {}
-
-  NS_IMETHOD
-  Run() override {
-    ScheduleStableStateRunnable::Run();
-
-    nsCOMPtr<nsIRunnable> runnable = new CheckStableStateRunnable(false);
-    if (NS_FAILED(NS_DispatchToCurrentThread(runnable))) {
-      fail("Failed to dispatch check runnable");
-    }
-
-    if (NS_FAILED(NS_ProcessPendingEvents(nullptr))) {
-      fail("Failed to process all pending events");
-    }
-
-    runnable = new CheckStableStateRunnable(true);
-    if (NS_FAILED(NS_DispatchToCurrentThread(runnable))) {
-      fail("Failed to dispatch check runnable");
-    }
-
-    runnable = new NextTestRunnable(mAppShell);
-    if (NS_FAILED(NS_DispatchToCurrentThread(runnable))) {
-      fail("Failed to dispatch next test runnable");
-    }
-
-    return NS_OK;
-  }
-};
-
-class EventListener final : public nsIDOMEventListener {
-  nsCOMPtr<nsIAppShell> mAppShell;
-
-  static nsIDOMWindowUtils* sWindowUtils;
-  static nsIAppShell* sAppShell;
-
-  ~EventListener() {}
-
- public:
-  NS_DECL_ISUPPORTS
-
-  explicit EventListener(nsIAppShell* aAppShell) : mAppShell(aAppShell) {}
-
-  NS_IMETHOD
-  HandleEvent(dom::Event* aEvent) override {
-    nsString type;
-    if (NS_FAILED(aEvent->GetType(type))) {
-      fail("Failed to get event type");
-      return NS_ERROR_FAILURE;
-    }
-
-    if (type.EqualsLiteral("load")) {
-      passed("Got load event");
-
-      nsCOMPtr<dom::Document> document = do_QueryInterface(aEvent->GetTarget());
-      if (!document) {
-        fail("Failed to QI to Document!");
-        return NS_ERROR_FAILURE;
-      }
-
-      nsCOMPtr<nsPIDOMWindowOuter> window = document->GetWindow();
-      if (!window) {
-        fail("Failed to get window from document!");
-        return NS_ERROR_FAILURE;
-      }
-
-      nsCOMPtr<nsIDOMWindowUtils> utils =
-          nsGlobalWindowOuter::Cast(window)->WindowUtils();
-
-      if (!ScheduleTimer(utils)) {
-        return NS_ERROR_FAILURE;
-      }
-
-      return NS_OK;
-    }
-
-    if (type.EqualsLiteral("keypress")) {
-      passed("Got keypress event");
-
-      nsCOMPtr<nsIRunnable> runnable = new StableStateRunnable();
-      nsresult rv = mAppShell->RunBeforeNextEvent(runnable);
-      if (NS_FAILED(rv)) {
-        fail("RunBeforeNextEvent returned failure code %u", rv);
-        return NS_ERROR_FAILURE;
-      }
-
-      return NS_OK;
-    }
-
-    fail("Got an unexpected event: %s", NS_ConvertUTF16toUTF8(type).get());
-    return NS_OK;
-  }
-
-#ifdef XP_WIN
-  static VOID CALLBACK TimerCallback(HWND hwnd, UINT uMsg, UINT idEvent,
-                                     DWORD dwTime) {
-    if (sWindowUtils) {
-      nsCOMPtr<nsIDOMWindowUtils> utils = dont_AddRef(sWindowUtils);
-      sWindowUtils = nullptr;
-
-      if (gStableStateEventHasRun) {
-        fail("StableStateRunnable ran at wrong time");
-      } else {
-        passed("StableStateRunnable state correct (false)");
-      }
-
-      int32_t layout = 0x409;  // US
-      int32_t keyCode = 0x41;  // VK_A
-      NS_NAMED_LITERAL_STRING(a, "a");
-
-      if (NS_FAILED(
-              utils->SendNativeKeyEvent(layout, keyCode, 0, a, a, nullptr))) {
-        fail("Failed to synthesize native event");
-      }
-
-      return;
-    }
-
-    KillTimer(nullptr, idEvent);
-
-    nsCOMPtr<nsIAppShell> appShell = dont_AddRef(sAppShell);
-
-    if (!gStableStateEventHasRun) {
-      fail("StableStateRunnable didn't run yet");
-    } else {
-      passed("StableStateRunnable state correct (true)");
-    }
-
-    nsCOMPtr<nsIRunnable> runnable = new NextTestRunnable(appShell);
-    if (NS_FAILED(NS_DispatchToCurrentThread(runnable))) {
-      fail("Failed to dispatch next test runnable");
-    }
-  }
-#endif
-
-  bool ScheduleTimer(nsIDOMWindowUtils* aWindowUtils) {
-#ifdef XP_WIN
-    UINT_PTR timerId = SetTimer(nullptr, 0, 1000, (TIMERPROC)TimerCallback);
-    if (!timerId) {
-      fail("SetTimer failed!");
-      return false;
-    }
-
-    nsCOMPtr<nsIDOMWindowUtils> utils = aWindowUtils;
-    utils.forget(&sWindowUtils);
-
-    nsCOMPtr<nsIAppShell> appShell = mAppShell;
-    appShell.forget(&sAppShell);
-
-    return true;
-#else
-    return false;
-#endif
-  }
-};
-
-nsIDOMWindowUtils* EventListener::sWindowUtils = nullptr;
-nsIAppShell* EventListener::sAppShell = nullptr;
-
-NS_IMPL_ISUPPORTS(EventListener, nsIDOMEventListener)
-
-already_AddRefed<nsIAppShell> GetAppShell() {
-  static const char* platforms[] = {"android", "mac", "gtk", "qt", "win"};
-
-  NS_NAMED_LITERAL_CSTRING(contractPrefix, "@mozilla.org/widget/appshell/");
-  NS_NAMED_LITERAL_CSTRING(contractSuffix, ";1");
-
-  for (size_t index = 0; index < ArrayLength(platforms); index++) {
-    nsAutoCString contractID(contractPrefix);
-    contractID.AppendASCII(platforms[index]);
-    contractID.Append(contractSuffix);
-
-    nsCOMPtr<nsIAppShell> appShell = do_GetService(contractID.get());
-    if (appShell) {
-      return appShell.forget();
-    }
-  }
-
-  return nullptr;
-}
-
-void Test1(nsIAppShell* aAppShell) {
-  // Schedule stable state runnable to be run before next event.
-
-  nsCOMPtr<nsIRunnable> runnable = new StableStateRunnable();
-  if (NS_FAILED(aAppShell->RunBeforeNextEvent(runnable))) {
-    fail("RunBeforeNextEvent failed");
-  }
-
-  runnable = new CheckStableStateRunnable(true);
-  if (NS_FAILED(NS_DispatchToCurrentThread(runnable))) {
-    fail("Failed to dispatch check runnable");
-  }
-
-  runnable = new NextTestRunnable(aAppShell);
-  if (NS_FAILED(NS_DispatchToCurrentThread(runnable))) {
-    fail("Failed to dispatch next test runnable");
-  }
-}
-
-void Test2(nsIAppShell* aAppShell) {
-  // Schedule stable state runnable to be run before next event from another
-  // runnable.
-
-  nsCOMPtr<nsIRunnable> runnable = new ScheduleStableStateRunnable(aAppShell);
-  if (NS_FAILED(NS_DispatchToCurrentThread(runnable))) {
-    fail("Failed to dispatch schedule runnable");
-  }
-
-  runnable = new CheckStableStateRunnable(true);
-  if (NS_FAILED(NS_DispatchToCurrentThread(runnable))) {
-    fail("Failed to dispatch check runnable");
-  }
-
-  runnable = new NextTestRunnable(aAppShell);
-  if (NS_FAILED(NS_DispatchToCurrentThread(runnable))) {
-    fail("Failed to dispatch next test runnable");
-  }
-}
-
-void Test3(nsIAppShell* aAppShell) {
-  // Schedule steadystate runnable to be run before next event with nested loop.
-
-  nsCOMPtr<nsIRunnable> runnable =
-      new ScheduleNestedStableStateRunnable(aAppShell);
-  if (NS_FAILED(NS_DispatchToCurrentThread(runnable))) {
-    fail("Failed to dispatch schedule runnable");
-  }
-}
-
-bool Test4Internal(nsIAppShell* aAppShell) {
-#ifndef XP_WIN
-  // Not sure how to test on other platforms.
-  return false;
-#else
-  nsCOMPtr<nsIAppShellService> appService =
-      do_GetService(NS_APPSHELLSERVICE_CONTRACTID);
-  if (!appService) {
-    fail("Failed to get appshell service!");
-    return false;
-  }
-
-  nsCOMPtr<nsIURI> uri;
-  if (NS_FAILED(NS_NewURI(getter_AddRefs(uri), "about:", nullptr))) {
-    fail("Failed to create new uri");
-    return false;
-  }
-
-  uint32_t flags = nsIWebBrowserChrome::CHROME_DEFAULT;
-
-  nsCOMPtr<nsIAppWindow> appWindow;
-  if (NS_FAILED(appService->CreateTopLevelWindow(
-          nullptr, uri, flags, 100, 100, nullptr, getter_AddRefs(appWindow)))) {
-    fail("Failed to create new window");
-    return false;
-  }
-
-  nsCOMPtr<nsIDOMWindow> window = do_GetInterface(appWindow);
-  if (!window) {
-    fail("Can't get dom window!");
-    return false;
-  }
-
-  RefPTr<dom::EventTarget> target = do_QueryInterface(window);
-  if (!target) {
-    fail("Can't QI to EventTarget!");
-    return false;
-  }
-
-  nsCOMPtr<nsIDOMEventListener> listener = new EventListener(aAppShell);
-  if (NS_FAILED(target->AddEventListener(NS_LITERAL_STRING("keypress"),
-                                         listener, false, false)) ||
-      NS_FAILED(target->AddEventListener(NS_LITERAL_STRING("load"), listener,
-                                         false, false))) {
-    fail("Can't add event listeners!");
-    return false;
-  }
-
-  return true;
-#endif
-}
-
-void Test4(nsIAppShell* aAppShell) {
-  if (!Test4Internal(aAppShell)) {
-    nsCOMPtr<nsIRunnable> runnable = new NextTestRunnable(aAppShell);
-    if (NS_FAILED(NS_DispatchToCurrentThread(runnable))) {
-      fail("Failed to dispatch next test runnable");
-    }
-  }
-}
-
-const TestFunc gTests[] = {Test1, Test2, Test3, Test4};
-
-size_t gTestIndex = 0;
-
-NS_IMETHODIMP
-NextTestRunnable::Run() {
-  if (gTestIndex > 0) {
-    passed("Finished test %u", gTestIndex);
-  }
-
-  gStableStateEventHasRun = false;
-
-  if (gTestIndex < ArrayLength(gTests)) {
-    gTests[gTestIndex++](mAppShell);
-  } else {
-    nsCOMPtr<nsIRunnable> exitRunnable = new ExitAppShellRunnable(mAppShell);
-
-    nsresult rv = NS_DispatchToCurrentThread(exitRunnable);
-    if (NS_FAILED(rv)) {
-      fail("Failed to dispatch exit runnable!");
-    }
-  }
-
-  return NS_OK;
-}
-
-int main(int argc, char** argv) {
-  ScopedLogging log;
-  ScopedXPCOM xpcom("TestAppShellSteadyState");
-
-  if (!xpcom.failed()) {
-    nsCOMPtr<nsIAppShell> appShell = GetAppShell();
-    if (!appShell) {
-      fail("Couldn't get appshell!");
-    } else {
-      nsCOMPtr<nsIRunnable> runnable = new NextTestRunnable(appShell);
-      if (NS_FAILED(NS_DispatchToCurrentThread(runnable))) {
-        fail("Failed to dispatch next test runnable");
-      } else if (NS_FAILED(appShell->Run())) {
-        fail("Failed to run appshell");
-      }
-    }
-  }
-
-  return gFailCount != 0;
-}

--- a/widget/tests/moz.build
+++ b/widget/tests/moz.build
@@ -8,19 +8,16 @@ with Files("**"):
     BUG_COMPONENT = ("Core", "Widget")
 
 with Files("unit/*macwebapputils*"):
     BUG_COMPONENT = ("Core", "Widget: Cocoa")
 
 with Files("unit/*taskbar_jumplistitems*"):
     BUG_COMPONENT = ("Core", "Widget: Win32")
 
-with Files("TestAppShellSteadyState.cpp"):
-    BUG_COMPONENT = ("Core", "Storage: IndexedDB")
-
 with Files("TestChromeMargin.cpp"):
     BUG_COMPONENT = ("Core", "Widget: Win32")
 
 with Files("*413277*"):
     BUG_COMPONENT = ("Core", "Widget: Cocoa")
 
 with Files("*428405*"):
     BUG_COMPONENT = ("Core", "Widget: Cocoa")