Adding upstream version 115.7.0esr.upstream/115.7.0esr

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 810 insertions, 0 deletions

diff --git a/widget/windows/nsAppShell.cpp b/widget/windows/nsAppShell.cpp
new file mode 100644
index 0000000000..704da730f2
--- /dev/null
+++ b/widget/windows/nsAppShell.cpp
@@ -0,0 +1,810 @@
+/* -*- Mode: c++; tab-width: 2; indent-tabs-mode: nil; -*- */
+/* 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 "mozilla/ipc/MessageChannel.h"
+#include "mozilla/ipc/WindowsMessageLoop.h"
+#include "nsAppShell.h"
+#include "nsToolkit.h"
+#include "nsThreadUtils.h"
+#include "WinUtils.h"
+#include "WinTaskbar.h"
+#include "WinMouseScrollHandler.h"
+#include "nsWindowDefs.h"
+#include "nsWindow.h"
+#include "nsString.h"
+#include "WinIMEHandler.h"
+#include "mozilla/widget/AudioSession.h"
+#include "mozilla/BackgroundHangMonitor.h"
+#include "mozilla/Hal.h"
+#include "nsIDOMWakeLockListener.h"
+#include "nsIPowerManagerService.h"
+#include "mozilla/ProfilerLabels.h"
+#include "mozilla/StaticPtr.h"
+#include "nsTHashtable.h"
+#include "nsHashKeys.h"
+#include "nsComponentManagerUtils.h"
+#include "ScreenHelperWin.h"
+#include "HeadlessScreenHelper.h"
+#include "mozilla/widget/ScreenManager.h"
+#include "mozilla/Atomics.h"
+#include "mozilla/WindowsProcessMitigations.h"
+#include "mozilla/WindowsVersion.h"
+
+#ifdef MOZ_BACKGROUNDTASKS
+#  include "mozilla/BackgroundTasks.h"
+#endif
+
+#if defined(ACCESSIBILITY)
+#  include "mozilla/a11y/Compatibility.h"
+#  include "mozilla/a11y/Platform.h"
+#endif  // defined(ACCESSIBILITY)
+
+using namespace mozilla;
+using namespace mozilla::widget;
+
+#define WAKE_LOCK_LOG(...) \
+  MOZ_LOG(gWinWakeLockLog, mozilla::LogLevel::Debug, (__VA_ARGS__))
+static mozilla::LazyLogModule gWinWakeLockLog("WinWakeLock");
+
+// This wakelock listener is used for Window7 and above.
+class WinWakeLockListener final : public nsIDOMMozWakeLockListener {
+ public:
+  NS_DECL_ISUPPORTS
+  WinWakeLockListener() { MOZ_ASSERT(XRE_IsParentProcess()); }
+
+ private:
+  ~WinWakeLockListener() {
+    ReleaseWakelockIfNeeded(PowerRequestDisplayRequired);
+    ReleaseWakelockIfNeeded(PowerRequestExecutionRequired);
+  }
+
+  void SetHandle(HANDLE aHandle, POWER_REQUEST_TYPE aType) {
+    switch (aType) {
+      case PowerRequestDisplayRequired: {
+        if (!aHandle && mDisplayHandle) {
+          CloseHandle(mDisplayHandle);
+        }
+        mDisplayHandle = aHandle;
+        return;
+      }
+      case PowerRequestExecutionRequired: {
+        if (!aHandle && mNonDisplayHandle) {
+          CloseHandle(mNonDisplayHandle);
+        }
+        mNonDisplayHandle = aHandle;
+        return;
+      }
+      default:
+        MOZ_ASSERT_UNREACHABLE("Invalid request type");
+        return;
+    }
+  }
+
+  HANDLE GetHandle(POWER_REQUEST_TYPE aType) const {
+    switch (aType) {
+      case PowerRequestDisplayRequired:
+        return mDisplayHandle;
+      case PowerRequestExecutionRequired:
+        return mNonDisplayHandle;
+      default:
+        MOZ_ASSERT_UNREACHABLE("Invalid request type");
+        return nullptr;
+    }
+  }
+
+  HANDLE CreateHandle(POWER_REQUEST_TYPE aType) {
+    MOZ_ASSERT(!GetHandle(aType));
+    REASON_CONTEXT context = {0};
+    context.Version = POWER_REQUEST_CONTEXT_VERSION;
+    context.Flags = POWER_REQUEST_CONTEXT_SIMPLE_STRING;
+    context.Reason.SimpleReasonString = RequestTypeLPWSTR(aType);
+    HANDLE handle = PowerCreateRequest(&context);
+    if (!handle) {
+      WAKE_LOCK_LOG("Failed to create handle for %s, error=%lu",
+                    RequestTypeStr(aType), GetLastError());
+      return nullptr;
+    }
+    SetHandle(handle, aType);
+    return handle;
+  }
+
+  LPWSTR RequestTypeLPWSTR(POWER_REQUEST_TYPE aType) const {
+    switch (aType) {
+      case PowerRequestDisplayRequired:
+        return const_cast<LPWSTR>(L"display request");  // -Wwritable-strings
+      case PowerRequestExecutionRequired:
+        return const_cast<LPWSTR>(
+            L"non-display request");  // -Wwritable-strings
+      default:
+        MOZ_ASSERT_UNREACHABLE("Invalid request type");
+        return const_cast<LPWSTR>(L"unknown");  // -Wwritable-strings
+    }
+  }
+
+  const char* RequestTypeStr(POWER_REQUEST_TYPE aType) const {
+    switch (aType) {
+      case PowerRequestDisplayRequired:
+        return "display request";
+      case PowerRequestExecutionRequired:
+        return "non-display request";
+      default:
+        MOZ_ASSERT_UNREACHABLE("Invalid request type");
+        return "unknown";
+    }
+  }
+
+  void RequestWakelockIfNeeded(POWER_REQUEST_TYPE aType) {
+    if (GetHandle(aType)) {
+      WAKE_LOCK_LOG("Already requested lock for %s", RequestTypeStr(aType));
+      return;
+    }
+
+    WAKE_LOCK_LOG("Prepare a wakelock for %s", RequestTypeStr(aType));
+    HANDLE handle = CreateHandle(aType);
+    if (!handle) {
+      WAKE_LOCK_LOG("Failed due to no handle for %s", RequestTypeStr(aType));
+      return;
+    }
+
+    if (PowerSetRequest(handle, aType)) {
+      WAKE_LOCK_LOG("Requested %s lock", RequestTypeStr(aType));
+    } else {
+      WAKE_LOCK_LOG("Failed to request %s lock, error=%lu",
+                    RequestTypeStr(aType), GetLastError());
+      SetHandle(nullptr, aType);
+    }
+  }
+
+  void ReleaseWakelockIfNeeded(POWER_REQUEST_TYPE aType) {
+    if (!GetHandle(aType)) {
+      WAKE_LOCK_LOG("Already released lock for %s", RequestTypeStr(aType));
+      return;
+    }
+
+    WAKE_LOCK_LOG("Prepare to release wakelock for %s", RequestTypeStr(aType));
+    if (!PowerClearRequest(GetHandle(aType), aType)) {
+      WAKE_LOCK_LOG("Failed to release %s lock, error=%lu",
+                    RequestTypeStr(aType), GetLastError());
+      return;
+    }
+    SetHandle(nullptr, aType);
+    WAKE_LOCK_LOG("Released wakelock for %s", RequestTypeStr(aType));
+  }
+
+  NS_IMETHOD Callback(const nsAString& aTopic,
+                      const nsAString& aState) override {
+    WAKE_LOCK_LOG("topic=%s, state=%s", NS_ConvertUTF16toUTF8(aTopic).get(),
+                  NS_ConvertUTF16toUTF8(aState).get());
+    if (!aTopic.EqualsASCII("screen") && !aTopic.EqualsASCII("audio-playing") &&
+        !aTopic.EqualsASCII("video-playing")) {
+      return NS_OK;
+    }
+
+    const bool isNonDisplayLock = aTopic.EqualsASCII("audio-playing");
+    bool requestLock = false;
+    if (isNonDisplayLock) {
+      requestLock = aState.EqualsASCII("locked-foreground") ||
+                    aState.EqualsASCII("locked-background");
+    } else {
+      requestLock = aState.EqualsASCII("locked-foreground");
+    }
+
+    if (isNonDisplayLock) {
+      if (requestLock) {
+        RequestWakelockIfNeeded(PowerRequestExecutionRequired);
+      } else {
+        ReleaseWakelockIfNeeded(PowerRequestExecutionRequired);
+      }
+    } else {
+      if (requestLock) {
+        RequestWakelockIfNeeded(PowerRequestDisplayRequired);
+      } else {
+        ReleaseWakelockIfNeeded(PowerRequestDisplayRequired);
+      }
+    }
+    return NS_OK;
+  }
+
+  // Handle would only exist when we request wakelock successfully.
+  HANDLE mDisplayHandle = nullptr;
+  HANDLE mNonDisplayHandle = nullptr;
+};
+NS_IMPL_ISUPPORTS(WinWakeLockListener, nsIDOMMozWakeLockListener)
+
+// This wakelock is used for the version older than Windows7.
+class LegacyWinWakeLockListener final : public nsIDOMMozWakeLockListener {
+ public:
+  NS_DECL_ISUPPORTS
+  LegacyWinWakeLockListener() { MOZ_ASSERT(XRE_IsParentProcess()); }
+
+ private:
+  ~LegacyWinWakeLockListener() {}
+
+  NS_IMETHOD Callback(const nsAString& aTopic,
+                      const nsAString& aState) override {
+    WAKE_LOCK_LOG("WinWakeLock: topic=%s, state=%s",
+                  NS_ConvertUTF16toUTF8(aTopic).get(),
+                  NS_ConvertUTF16toUTF8(aState).get());
+    if (!aTopic.EqualsASCII("screen") && !aTopic.EqualsASCII("audio-playing") &&
+        !aTopic.EqualsASCII("video-playing")) {
+      return NS_OK;
+    }
+
+    // Check what kind of lock we will require, if both display lock and non
+    // display lock are needed, we would require display lock because it has
+    // higher priority.
+    if (aTopic.EqualsASCII("audio-playing")) {
+      mRequireForNonDisplayLock = aState.EqualsASCII("locked-foreground") ||
+                                  aState.EqualsASCII("locked-background");
+    } else if (aTopic.EqualsASCII("screen") ||
+               aTopic.EqualsASCII("video-playing")) {
+      mRequireForDisplayLock = aState.EqualsASCII("locked-foreground");
+    }
+
+    if (mRequireForDisplayLock) {
+      WAKE_LOCK_LOG("WinWakeLock: Request display lock");
+      SetThreadExecutionState(ES_DISPLAY_REQUIRED | ES_CONTINUOUS);
+    } else if (mRequireForNonDisplayLock) {
+      WAKE_LOCK_LOG("WinWakeLock: Request non-display lock");
+      SetThreadExecutionState(ES_SYSTEM_REQUIRED | ES_CONTINUOUS);
+    } else {
+      WAKE_LOCK_LOG("WinWakeLock: reset lock");
+      SetThreadExecutionState(ES_CONTINUOUS);
+    }
+    return NS_OK;
+  }
+
+  bool mRequireForDisplayLock = false;
+  bool mRequireForNonDisplayLock = false;
+};
+
+NS_IMPL_ISUPPORTS(LegacyWinWakeLockListener, nsIDOMMozWakeLockListener)
+StaticRefPtr<nsIDOMMozWakeLockListener> sWakeLockListener;
+
+static void AddScreenWakeLockListener() {
+  nsCOMPtr<nsIPowerManagerService> sPowerManagerService =
+      do_GetService(POWERMANAGERSERVICE_CONTRACTID);
+  if (sPowerManagerService) {
+    if (IsWin7SP1OrLater()) {
+      sWakeLockListener = new WinWakeLockListener();
+    } else {
+      sWakeLockListener = new LegacyWinWakeLockListener();
+    }
+    sPowerManagerService->AddWakeLockListener(sWakeLockListener);
+  } else {
+    NS_WARNING(
+        "Failed to retrieve PowerManagerService, wakelocks will be broken!");
+  }
+}
+
+static void RemoveScreenWakeLockListener() {
+  nsCOMPtr<nsIPowerManagerService> sPowerManagerService =
+      do_GetService(POWERMANAGERSERVICE_CONTRACTID);
+  if (sPowerManagerService) {
+    sPowerManagerService->RemoveWakeLockListener(sWakeLockListener);
+    sPowerManagerService = nullptr;
+    sWakeLockListener = nullptr;
+  }
+}
+
+class SingleNativeEventPump final : public nsIThreadObserver {
+ public:
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSITHREADOBSERVER
+
+  SingleNativeEventPump() {
+    MOZ_ASSERT(!XRE_UseNativeEventProcessing(),
+               "Should only be used when not properly processing events.");
+  }
+
+ private:
+  ~SingleNativeEventPump() {}
+};
+
+NS_IMPL_ISUPPORTS(SingleNativeEventPump, nsIThreadObserver)
+
+NS_IMETHODIMP
+SingleNativeEventPump::OnDispatchedEvent() { return NS_OK; }
+
+NS_IMETHODIMP
+SingleNativeEventPump::OnProcessNextEvent(nsIThreadInternal* aThread,
+                                          bool aMayWait) {
+  MSG msg;
+  bool gotMessage = WinUtils::PeekMessage(&msg, nullptr, 0, 0, PM_REMOVE);
+  if (gotMessage) {
+    ::TranslateMessage(&msg);
+    ::DispatchMessageW(&msg);
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+SingleNativeEventPump::AfterProcessNextEvent(nsIThreadInternal* aThread,
+                                             bool aMayWait) {
+  return NS_OK;
+}
+
+// RegisterWindowMessage values
+// Native event callback message
+const wchar_t* kAppShellGeckoEventId = L"nsAppShell:EventID";
+UINT sAppShellGeckoMsgId;
+// Taskbar button creation message
+const wchar_t* kTaskbarButtonEventId = L"TaskbarButtonCreated";
+UINT sTaskbarButtonCreatedMsg;
+
+/* static */
+UINT nsAppShell::GetTaskbarButtonCreatedMessage() {
+  return sTaskbarButtonCreatedMsg;
+}
+
+namespace mozilla {
+namespace crashreporter {
+void LSPAnnotate();
+}  // namespace crashreporter
+}  // namespace mozilla
+
+using mozilla::crashreporter::LSPAnnotate;
+
+//-------------------------------------------------------------------------
+
+// Note that since we're on x86-ish processors here, ReleaseAcquire is the
+// semantics that normal loads and stores would use anyway.
+static Atomic<size_t, ReleaseAcquire> sOutstandingNativeEventCallbacks;
+
+/*static*/ LRESULT CALLBACK nsAppShell::EventWindowProc(HWND hwnd, UINT uMsg,
+                                                        WPARAM wParam,
+                                                        LPARAM lParam) {
+  if (uMsg == sAppShellGeckoMsgId) {
+    // The app shell might have been destroyed between this message being
+    // posted and being executed, so be extra careful.
+    if (!sOutstandingNativeEventCallbacks) {
+      return TRUE;
+    }
+
+    nsAppShell* as = reinterpret_cast<nsAppShell*>(lParam);
+    as->NativeEventCallback();
+    --sOutstandingNativeEventCallbacks;
+    return TRUE;
+  }
+  return DefWindowProc(hwnd, uMsg, wParam, lParam);
+}
+
+nsAppShell::~nsAppShell() {
+  hal::Shutdown();
+
+  if (mEventWnd) {
+    // DestroyWindow doesn't do anything when called from a non UI thread.
+    // Since mEventWnd was created on the UI thread, it must be destroyed on
+    // the UI thread.
+    SendMessage(mEventWnd, WM_CLOSE, 0, 0);
+  }
+
+  // Cancel any outstanding native event callbacks.
+  sOutstandingNativeEventCallbacks = 0;
+}
+
+#if defined(ACCESSIBILITY)
+
+static ULONG gUiaMsg;
+static HHOOK gUiaHook;
+static uint32_t gUiaAttempts;
+static const uint32_t kMaxUiaAttempts = 5;
+
+static void InitUIADetection();
+
+static LRESULT CALLBACK UiaHookProc(int aCode, WPARAM aWParam, LPARAM aLParam) {
+  if (aCode < 0) {
+    return ::CallNextHookEx(nullptr, aCode, aWParam, aLParam);
+  }
+
+  auto cwp = reinterpret_cast<CWPSTRUCT*>(aLParam);
+  if (gUiaMsg && cwp->message == gUiaMsg) {
+    if (gUiaAttempts < kMaxUiaAttempts) {
+      ++gUiaAttempts;
+
+      Maybe<bool> shouldCallNextHook =
+          a11y::Compatibility::OnUIAMessage(cwp->wParam, cwp->lParam);
+      if (shouldCallNextHook.isSome()) {
+        // We've got an instantiator.
+        if (!shouldCallNextHook.value()) {
+          // We're blocking this instantiation. We need to keep this hook set
+          // so that we can catch any future instantiation attempts.
+          return 0;
+        }
+
+        // We're allowing the instantiator to proceed, so this hook is no longer
+        // needed.
+        if (::UnhookWindowsHookEx(gUiaHook)) {
+          gUiaHook = nullptr;
+        }
+      } else {
+        // Our hook might be firing after UIA; let's try reinstalling ourselves.
+        InitUIADetection();
+      }
+    } else {
+      // We've maxed out our attempts. Let's unhook.
+      if (::UnhookWindowsHookEx(gUiaHook)) {
+        gUiaHook = nullptr;
+      }
+    }
+  }
+
+  return ::CallNextHookEx(nullptr, aCode, aWParam, aLParam);
+}
+
+static void InitUIADetection() {
+  if (gUiaHook) {
+    // In this case we want to re-hook so that the hook is always called ahead
+    // of UIA's hook.
+    if (::UnhookWindowsHookEx(gUiaHook)) {
+      gUiaHook = nullptr;
+    }
+  }
+
+  if (!gUiaMsg) {
+    // This is the message that UIA sends to trigger a command. UIA's
+    // CallWndProc looks for this message and then handles the request.
+    // Our hook gets in front of UIA's hook and examines the message first.
+    gUiaMsg = ::RegisterWindowMessageW(L"HOOKUTIL_MSG");
+  }
+
+  if (!gUiaHook) {
+    gUiaHook = ::SetWindowsHookEx(WH_CALLWNDPROC, &UiaHookProc, nullptr,
+                                  ::GetCurrentThreadId());
+  }
+}
+
+#endif  // defined(ACCESSIBILITY)
+
+NS_IMETHODIMP
+nsAppShell::Observe(nsISupports* aSubject, const char* aTopic,
+                    const char16_t* aData) {
+  if (XRE_IsParentProcess()) {
+    nsCOMPtr<nsIObserverService> obsServ(
+        mozilla::services::GetObserverService());
+
+#if defined(ACCESSIBILITY)
+    if (!strcmp(aTopic, "dll-loaded-main-thread")) {
+      if (a11y::PlatformDisabledState() != a11y::ePlatformIsDisabled &&
+          !gUiaHook) {
+        nsDependentString dllName(aData);
+
+        if (StringEndsWith(dllName, u"uiautomationcore.dll"_ns,
+                           nsCaseInsensitiveStringComparator)) {
+          InitUIADetection();
+
+          // Now that we've handled the observer notification, we can remove it
+          obsServ->RemoveObserver(this, "dll-loaded-main-thread");
+        }
+      }
+
+      return NS_OK;
+    }
+#endif  // defined(ACCESSIBILITY)
+
+    if (!strcmp(aTopic, "sessionstore-restoring-on-startup")) {
+      nsWindow::SetIsRestoringSession(true);
+      // Now that we've handled the observer notification, we can remove it
+      obsServ->RemoveObserver(this, "sessionstore-restoring-on-startup");
+      return NS_OK;
+    }
+
+    if (!strcmp(aTopic, "sessionstore-windows-restored")) {
+      nsWindow::SetIsRestoringSession(false);
+      // Now that we've handled the observer notification, we can remove it
+      obsServ->RemoveObserver(this, "sessionstore-windows-restored");
+      return NS_OK;
+    }
+  }
+
+  return nsBaseAppShell::Observe(aSubject, aTopic, aData);
+}
+
+nsresult nsAppShell::Init() {
+  LSPAnnotate();
+
+  hal::Init();
+
+  if (XRE_IsParentProcess()) {
+    sTaskbarButtonCreatedMsg = ::RegisterWindowMessageW(kTaskbarButtonEventId);
+    NS_ASSERTION(sTaskbarButtonCreatedMsg,
+                 "Could not register taskbar button creation message");
+  }
+
+  // The hidden message window is used for interrupting the processing of native
+  // events, so that we can process gecko events. Therefore, we only need it if
+  // we are processing native events. Disabling this is required for win32k
+  // syscall lockdown.
+  if (XRE_UseNativeEventProcessing()) {
+    sAppShellGeckoMsgId = ::RegisterWindowMessageW(kAppShellGeckoEventId);
+    NS_ASSERTION(sAppShellGeckoMsgId,
+                 "Could not register hidden window event message!");
+
+    mLastNativeEventScheduled = TimeStamp::NowLoRes();
+
+    WNDCLASSW wc;
+    HINSTANCE module = GetModuleHandle(nullptr);
+
+    const wchar_t* const kWindowClass = L"nsAppShell:EventWindowClass";
+    if (!GetClassInfoW(module, kWindowClass, &wc)) {
+      wc.style = 0;
+      wc.lpfnWndProc = EventWindowProc;
+      wc.cbClsExtra = 0;
+      wc.cbWndExtra = 0;
+      wc.hInstance = module;
+      wc.hIcon = nullptr;
+      wc.hCursor = nullptr;
+      wc.hbrBackground = (HBRUSH) nullptr;
+      wc.lpszMenuName = (LPCWSTR) nullptr;
+      wc.lpszClassName = kWindowClass;
+      [[maybe_unused]] ATOM wcA = RegisterClassW(&wc);
+      MOZ_DIAGNOSTIC_ASSERT(wcA, "RegisterClassW for EventWindowClass failed");
+    }
+
+    mEventWnd = CreateWindowW(kWindowClass, L"nsAppShell:EventWindow", 0, 0, 0,
+                              10, 10, HWND_MESSAGE, nullptr, module, nullptr);
+    MOZ_DIAGNOSTIC_ASSERT(mEventWnd, "CreateWindowW for EventWindow failed");
+    NS_ENSURE_STATE(mEventWnd);
+  } else if (XRE_IsContentProcess() && !IsWin32kLockedDown()) {
+    // We're not generally processing native events, but still using GDI and we
+    // still have some internal windows, e.g. from calling CoInitializeEx.
+    // So we use a class that will do a single event pump where previously we
+    // might have processed multiple events to make sure any occasional messages
+    // to these windows are processed. This also allows any internal Windows
+    // messages to be processed to ensure the GDI data remains fresh.
+    nsCOMPtr<nsIThreadInternal> threadInt =
+        do_QueryInterface(NS_GetCurrentThread());
+    if (threadInt) {
+      threadInt->SetObserver(new SingleNativeEventPump());
+    }
+  }
+
+  if (XRE_IsParentProcess()) {
+    ScreenManager& screenManager = ScreenManager::GetSingleton();
+    if (gfxPlatform::IsHeadless()) {
+      screenManager.SetHelper(mozilla::MakeUnique<HeadlessScreenHelper>());
+    } else {
+      screenManager.SetHelper(mozilla::MakeUnique<ScreenHelperWin>());
+      ScreenHelperWin::RefreshScreens();
+    }
+
+    nsCOMPtr<nsIObserverService> obsServ(
+        mozilla::services::GetObserverService());
+
+    obsServ->AddObserver(this, "sessionstore-restoring-on-startup", false);
+    obsServ->AddObserver(this, "sessionstore-windows-restored", false);
+
+#if defined(ACCESSIBILITY)
+    if (::GetModuleHandleW(L"uiautomationcore.dll")) {
+      InitUIADetection();
+    } else {
+      obsServ->AddObserver(this, "dll-loaded-main-thread", false);
+    }
+#endif  // defined(ACCESSIBILITY)
+  }
+
+  if (!WinUtils::GetTimezoneName(mTimezoneName)) {
+    NS_WARNING("Unable to get system timezone name, timezone may be invalid\n");
+  }
+
+  return nsBaseAppShell::Init();
+}
+
+NS_IMETHODIMP
+nsAppShell::Run(void) {
+  bool wantAudio = true;
+  if (XRE_IsParentProcess()) {
+#ifdef MOZ_BACKGROUNDTASKS
+    if (BackgroundTasks::IsBackgroundTaskMode()) {
+      wantAudio = false;
+    }
+#endif
+    if (MOZ_LIKELY(wantAudio)) {
+      mozilla::widget::StartAudioSession();
+    }
+
+    // Add an observer that disables the screen saver when requested by Gecko.
+    // For example when we're playing video in the foreground tab. Whole firefox
+    // only needs one wakelock instance, so we would only create one listener in
+    // chrome process to prevent requesting unnecessary wakelock.
+    AddScreenWakeLockListener();
+  }
+
+  nsresult rv = nsBaseAppShell::Run();
+
+  if (XRE_IsParentProcess()) {
+    RemoveScreenWakeLockListener();
+
+    if (MOZ_LIKELY(wantAudio)) {
+      mozilla::widget::StopAudioSession();
+    }
+  }
+
+  return rv;
+}
+
+NS_IMETHODIMP
+nsAppShell::Exit(void) {
+#if defined(ACCESSIBILITY)
+  if (XRE_IsParentProcess()) {
+    nsCOMPtr<nsIObserverService> obsServ(
+        mozilla::services::GetObserverService());
+    obsServ->RemoveObserver(this, "dll-loaded-main-thread");
+
+    if (gUiaHook && ::UnhookWindowsHookEx(gUiaHook)) {
+      gUiaHook = nullptr;
+    }
+  }
+#endif  // defined(ACCESSIBILITY)
+
+  return nsBaseAppShell::Exit();
+}
+
+void nsAppShell::DoProcessMoreGeckoEvents() {
+  // Called by nsBaseAppShell's NativeEventCallback() after it has finished
+  // processing pending gecko events and there are still gecko events pending
+  // for the thread. (This can happen if NS_ProcessPendingEvents reached it's
+  // starvation timeout limit.) The default behavior in nsBaseAppShell is to
+  // call ScheduleNativeEventCallback to post a follow up native event callback
+  // message. This triggers an additional call to NativeEventCallback for more
+  // gecko event processing.
+
+  // There's a deadlock risk here with certain internal Windows modal loops. In
+  // our dispatch code, we prioritize messages so that input is handled first.
+  // However Windows modal dispatch loops often prioritize posted messages. If
+  // we find ourselves in a tight gecko timer loop where NS_ProcessPendingEvents
+  // takes longer than the timer duration, NS_HasPendingEvents(thread) will
+  // always be true. ScheduleNativeEventCallback will be called on every
+  // NativeEventCallback callback, and in a Windows modal dispatch loop, the
+  // callback message will be processed first -> input gets starved, dead lock.
+
+  // To avoid, don't post native callback messages from NativeEventCallback
+  // when we're in a modal loop. This gets us back into the Windows modal
+  // dispatch loop dispatching input messages. Once we drop out of the modal
+  // loop, we use mNativeCallbackPending to fire off a final NativeEventCallback
+  // if we need it, which insures NS_ProcessPendingEvents gets called and all
+  // gecko events get processed.
+  if (mEventloopNestingLevel < 2) {
+    OnDispatchedEvent();
+    mNativeCallbackPending = false;
+  } else {
+    mNativeCallbackPending = true;
+  }
+}
+
+void nsAppShell::ScheduleNativeEventCallback() {
+  MOZ_ASSERT(mEventWnd,
+             "We should have created mEventWnd in Init, if this is called.");
+
+  // Post a message to the hidden message window
+  ++sOutstandingNativeEventCallbacks;
+  {
+    MutexAutoLock lock(mLastNativeEventScheduledMutex);
+    // Time stamp this event so we can detect cases where the event gets
+    // dropping in sub classes / modal loops we do not control.
+    mLastNativeEventScheduled = TimeStamp::NowLoRes();
+  }
+  ::PostMessage(mEventWnd, sAppShellGeckoMsgId, 0,
+                reinterpret_cast<LPARAM>(this));
+}
+
+bool nsAppShell::ProcessNextNativeEvent(bool mayWait) {
+  // Notify ipc we are spinning a (possibly nested) gecko event loop.
+  mozilla::ipc::MessageChannel::NotifyGeckoEventDispatch();
+
+  bool gotMessage = false;
+
+  do {
+    MSG msg;
+
+    // For avoiding deadlock between our process and plugin process by
+    // mouse wheel messages, we're handling actually when we receive one of
+    // following internal messages which is posted by native mouse wheel
+    // message handler. Any other events, especially native modifier key
+    // events, should not be handled between native message and posted
+    // internal message because it may make different modifier key state or
+    // mouse cursor position between them.
+    if (mozilla::widget::MouseScrollHandler::IsWaitingInternalMessage()) {
+      gotMessage = WinUtils::PeekMessage(&msg, nullptr, MOZ_WM_MOUSEWHEEL_FIRST,
+                                         MOZ_WM_MOUSEWHEEL_LAST, PM_REMOVE);
+      NS_ASSERTION(gotMessage,
+                   "waiting internal wheel message, but it has not come");
+    }
+
+    if (!gotMessage) {
+      gotMessage = WinUtils::PeekMessage(&msg, nullptr, 0, 0, PM_REMOVE);
+    }
+
+    if (gotMessage) {
+      if (msg.message == WM_QUIT) {
+        ::PostQuitMessage(msg.wParam);
+        Exit();
+      } else {
+        // If we had UI activity we would be processing it now so we know we
+        // have either kUIActivity or kActivityNoUIAVail.
+        mozilla::BackgroundHangMonitor().NotifyActivity();
+
+        if (msg.message >= WM_KEYFIRST && msg.message <= WM_KEYLAST &&
+            IMEHandler::ProcessRawKeyMessage(msg)) {
+          continue;  // the message is consumed.
+        }
+
+#if defined(_X86_)
+        // Store Printer dialog messages for reposting on x86, because on x86
+        // Windows 7 they are not processed by a window procedure, but are
+        // explicitly waited for in the winspool.drv code that will be further
+        // up the stack (winspool!WaitForCompletionMessage). These are
+        // undocumented Windows Message identifiers found in winspool.drv.
+        if (msg.message == 0x5b7a || msg.message == 0x5b7f ||
+            msg.message == 0x5b80 || msg.message == 0x5b81) {
+          mMsgsToRepost.push_back(msg);
+          continue;
+        }
+#endif
+
+        // Windows documentation suggets that WM_SETTINGSCHANGE is the message
+        // to watch for timezone changes, but experimentation showed that it
+        // doesn't fire on changing the timezone, but that WM_TIMECHANGE does,
+        // even if there's no immediate effect on the clock (e.g., changing
+        // from Pacific Daylight at UTC-7 to Arizona at UTC-7).
+        if (msg.message == WM_TIMECHANGE) {
+          // The message may not give us sufficient information to determine
+          // if the timezone changed, so keep track of it ourselves.
+          wchar_t systemTimezone[128];
+          bool getSystemTimeSucceeded =
+              WinUtils::GetTimezoneName(systemTimezone);
+          if (getSystemTimeSucceeded && wcscmp(systemTimezone, mTimezoneName)) {
+            nsBaseAppShell::OnSystemTimezoneChange();
+
+            wcscpy_s(mTimezoneName, 128, systemTimezone);
+          }
+        }
+
+        ::TranslateMessage(&msg);
+        ::DispatchMessageW(&msg);
+      }
+    } else if (mayWait) {
+      // Block and wait for any posted application message
+      mozilla::BackgroundHangMonitor().NotifyWait();
+      {
+        AUTO_PROFILER_LABEL("nsAppShell::ProcessNextNativeEvent::Wait", IDLE);
+        WinUtils::WaitForMessage();
+      }
+    }
+  } while (!gotMessage && mayWait);
+
+  // See DoProcessNextNativeEvent, mEventloopNestingLevel will be
+  // one when a modal loop unwinds.
+  if (mNativeCallbackPending && mEventloopNestingLevel == 1)
+    DoProcessMoreGeckoEvents();
+
+  // Check for starved native callbacks. If we haven't processed one
+  // of these events in NATIVE_EVENT_STARVATION_LIMIT, fire one off.
+  static const mozilla::TimeDuration nativeEventStarvationLimit =
+      mozilla::TimeDuration::FromSeconds(NATIVE_EVENT_STARVATION_LIMIT);
+
+  TimeDuration timeSinceLastNativeEventScheduled;
+  {
+    MutexAutoLock lock(mLastNativeEventScheduledMutex);
+    timeSinceLastNativeEventScheduled =
+        TimeStamp::NowLoRes() - mLastNativeEventScheduled;
+  }
+  if (timeSinceLastNativeEventScheduled > nativeEventStarvationLimit) {
+    ScheduleNativeEventCallback();
+  }
+
+  return gotMessage;
+}
+
+nsresult nsAppShell::AfterProcessNextEvent(nsIThreadInternal* /* unused */,
+                                           bool /* unused */) {
+  if (!mMsgsToRepost.empty()) {
+    for (MSG msg : mMsgsToRepost) {
+      ::PostMessageW(msg.hwnd, msg.message, msg.wParam, msg.lParam);
+    }
+    mMsgsToRepost.clear();
+  }
+  return NS_OK;
+}