Adding upstream version 115.7.0esr.upstream/115.7.0esr

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

1 files changed, 6153 insertions, 0 deletions

diff --git a/toolkit/xre/nsAppRunner.cpp b/toolkit/xre/nsAppRunner.cpp
new file mode 100644
index 0000000000..14b8c98dc8
--- /dev/null
+++ b/toolkit/xre/nsAppRunner.cpp
@@ -0,0 +1,6153 @@
+/* -*- 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 "mozilla/dom/ContentParent.h"
+#include "mozilla/dom/ContentChild.h"
+#include "mozilla/ipc/GeckoChildProcessHost.h"
+
+#include "mozilla/AppShutdown.h"
+#include "mozilla/ArrayUtils.h"
+#include "mozilla/Assertions.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/Components.h"
+#include "mozilla/FilePreferences.h"
+#include "mozilla/ChaosMode.h"
+#include "mozilla/CmdLineAndEnvUtils.h"
+#include "mozilla/IOInterposer.h"
+#include "mozilla/ipc/UtilityProcessChild.h"
+#include "mozilla/Likely.h"
+#include "mozilla/MemoryChecking.h"
+#include "mozilla/Poison.h"
+#include "mozilla/Preferences.h"
+#include "mozilla/Printf.h"
+#include "mozilla/ProcessType.h"
+#include "mozilla/ResultExtensions.h"
+#include "mozilla/RuntimeExceptionModule.h"
+#include "mozilla/ScopeExit.h"
+#include "mozilla/StaticPrefs_browser.h"
+#include "mozilla/StaticPrefs_fission.h"
+#include "mozilla/StaticPrefs_webgl.h"
+#include "mozilla/StaticPrefs_widget.h"
+#include "mozilla/Telemetry.h"
+#include "mozilla/Utf8.h"
+#include "mozilla/intl/LocaleService.h"
+#include "mozilla/JSONWriter.h"
+#include "mozilla/gfx/gfxVars.h"
+#include "mozilla/glean/GleanPings.h"
+#include "mozilla/widget/TextRecognition.h"
+#include "BaseProfiler.h"
+
+#include "nsAppRunner.h"
+#include "mozilla/XREAppData.h"
+#include "mozilla/Bootstrap.h"
+#if defined(MOZ_UPDATER) && !defined(MOZ_WIDGET_ANDROID)
+#  include "nsUpdateDriver.h"
+#  include "nsUpdateSyncManager.h"
+#endif
+#include "ProfileReset.h"
+
+#ifdef MOZ_INSTRUMENT_EVENT_LOOP
+#  include "EventTracer.h"
+#endif
+
+#ifdef XP_MACOSX
+#  include "nsVersionComparator.h"
+#  include "MacLaunchHelper.h"
+#  include "MacApplicationDelegate.h"
+#  include "MacAutoreleasePool.h"
+#  include "MacRunFromDmgUtils.h"
+// these are needed for sysctl
+#  include <sys/types.h>
+#  include <sys/sysctl.h>
+#endif
+
+#include "prnetdb.h"
+#include "prprf.h"
+#include "prproces.h"
+#include "prenv.h"
+#include "prtime.h"
+
+#include "nsIAppStartup.h"
+#include "nsCategoryManagerUtils.h"
+#include "nsIMutableArray.h"
+#include "nsCommandLine.h"
+#include "nsIComponentRegistrar.h"
+#include "nsIDialogParamBlock.h"
+#include "mozilla/ModuleUtils.h"
+#include "nsIIOService.h"
+#include "nsIObserverService.h"
+#include "nsINativeAppSupport.h"
+#include "nsIPlatformInfo.h"
+#include "nsIProcess.h"
+#include "nsIProfileUnlocker.h"
+#include "nsIPromptService.h"
+#include "nsIPropertyBag2.h"
+#include "nsIServiceManager.h"
+#include "nsIStringBundle.h"
+#include "nsISupportsPrimitives.h"
+#include "nsIToolkitProfile.h"
+#include "nsToolkitProfileService.h"
+#include "nsIURI.h"
+#include "nsIURL.h"
+#include "nsIWindowCreator.h"
+#include "nsIWindowWatcher.h"
+#include "nsIXULAppInfo.h"
+#include "nsIXULRuntime.h"
+#include "nsPIDOMWindow.h"
+#include "nsIWidget.h"
+#include "nsAppShellCID.h"
+#include "mozilla/dom/quota/QuotaManager.h"
+#include "mozilla/scache/StartupCache.h"
+#include "gfxPlatform.h"
+#include "PDMFactory.h"
+#ifdef XP_MACOSX
+#  include "gfxPlatformMac.h"
+#endif
+
+#include "mozilla/Unused.h"
+
+#ifdef XP_WIN
+#  include "nsIWinAppHelper.h"
+#  include <windows.h>
+#  include <intrin.h>
+#  include <math.h>
+#  include "cairo/cairo-features.h"
+#  include "detect_win32k_conflicts.h"
+#  include "mozilla/PreXULSkeletonUI.h"
+#  include "mozilla/DllPrefetchExperimentRegistryInfo.h"
+#  include "mozilla/WindowsBCryptInitialization.h"
+#  include "mozilla/WindowsDllBlocklist.h"
+#  include "mozilla/WindowsProcessMitigations.h"
+#  include "mozilla/WinHeaderOnlyUtils.h"
+#  include "mozilla/mscom/ProcessRuntime.h"
+#  include "mozilla/mscom/ProfilerMarkers.h"
+#  include "WinTokenUtils.h"
+
+#  if defined(MOZ_LAUNCHER_PROCESS)
+#    include "mozilla/LauncherRegistryInfo.h"
+#  endif
+
+#  if defined(MOZ_DEFAULT_BROWSER_AGENT)
+#    include "nsIWindowsRegKey.h"
+#  endif
+
+#  ifndef PROCESS_DEP_ENABLE
+#    define PROCESS_DEP_ENABLE 0x1
+#  endif
+#endif
+
+#if defined(MOZ_SANDBOX)
+#  include "mozilla/SandboxSettings.h"
+#endif
+
+#ifdef ACCESSIBILITY
+#  include "nsAccessibilityService.h"
+#  if defined(XP_WIN)
+#    include "mozilla/a11y/Compatibility.h"
+#    include "mozilla/a11y/Platform.h"
+#  endif
+#endif
+
+#include "nsCRT.h"
+#include "nsCOMPtr.h"
+#include "nsDirectoryServiceDefs.h"
+#include "nsDirectoryServiceUtils.h"
+#include "nsEmbedCID.h"
+#include "nsIDUtils.h"
+#include "nsNetUtil.h"
+#include "nsReadableUtils.h"
+#include "nsXPCOM.h"
+#include "nsXPCOMCIDInternal.h"
+#include "nsString.h"
+#include "nsPrintfCString.h"
+#include "nsVersionComparator.h"
+
+#include "nsAppDirectoryServiceDefs.h"
+#include "nsXULAppAPI.h"
+#include "nsXREDirProvider.h"
+
+#include "nsINIParser.h"
+#include "mozilla/Omnijar.h"
+#include "mozilla/StartupTimeline.h"
+#include "mozilla/LateWriteChecks.h"
+
+#include <stdlib.h>
+#include <locale.h>
+
+#ifdef XP_UNIX
+#  include <errno.h>
+#  include <pwd.h>
+#  include <string.h>
+#  include <sys/resource.h>
+#  include <sys/stat.h>
+#  include <unistd.h>
+#endif
+
+#ifdef XP_WIN
+#  include <process.h>
+#  include <shlobj.h>
+#  include "mozilla/WinDllServices.h"
+#  include "nsThreadUtils.h"
+#  include "WinUtils.h"
+#endif
+
+#ifdef XP_MACOSX
+#  include "nsILocalFileMac.h"
+#  include "nsCommandLineServiceMac.h"
+#endif
+
+// for X remote support
+#if defined(MOZ_HAS_REMOTE)
+#  include "nsRemoteService.h"
+#endif
+
+#if defined(DEBUG) && defined(XP_WIN)
+#  include <malloc.h>
+#endif
+
+#if defined(XP_MACOSX)
+#  include <Carbon/Carbon.h>
+#endif
+
+#ifdef DEBUG
+#  include "mozilla/Logging.h"
+#endif
+
+#ifdef MOZ_JPROF
+#  include "jprof.h"
+#endif
+
+#include "nsExceptionHandler.h"
+#include "nsICrashReporter.h"
+#include "nsIPrefService.h"
+#include "nsIMemoryInfoDumper.h"
+#if defined(XP_LINUX) && !defined(ANDROID)
+#  include "mozilla/widget/LSBUtils.h"
+#endif
+
+#include "base/command_line.h"
+#include "GTestRunner.h"
+
+#ifdef MOZ_WIDGET_ANDROID
+#  include "mozilla/java/GeckoAppShellWrappers.h"
+#endif
+
+#if defined(MOZ_SANDBOX)
+#  if defined(XP_LINUX) && !defined(ANDROID)
+#    include "mozilla/SandboxInfo.h"
+#  elif defined(XP_WIN)
+#    include "sandboxBroker.h"
+#  endif
+#endif
+
+#ifdef MOZ_CODE_COVERAGE
+#  include "mozilla/CodeCoverageHandler.h"
+#endif
+
+#include "SafeMode.h"
+
+#ifdef MOZ_BACKGROUNDTASKS
+#  include "mozilla/BackgroundTasks.h"
+#  include "nsIPowerManagerService.h"
+#  include "nsIStringBundle.h"
+#endif
+
+#ifdef USE_GLX_TEST
+#  include "mozilla/GUniquePtr.h"
+#  include "mozilla/GfxInfo.h"
+#endif
+
+extern uint32_t gRestartMode;
+extern void InstallSignalHandlers(const char* ProgramName);
+
+#define FILE_COMPATIBILITY_INFO "compatibility.ini"_ns
+#define FILE_INVALIDATE_CACHES ".purgecaches"_ns
+#define FILE_STARTUP_INCOMPLETE u".startup-incomplete"_ns
+
+#if defined(MOZ_BLOCK_PROFILE_DOWNGRADE) || defined(MOZ_LAUNCHER_PROCESS) || \
+    defined(MOZ_DEFAULT_BROWSER_AGENT)
+static const char kPrefHealthReportUploadEnabled[] =
+    "datareporting.healthreport.uploadEnabled";
+#endif  // defined(MOZ_BLOCK_PROFILE_DOWNGRADE) || defined(MOZ_LAUNCHER_PROCESS)
+        // || defined(MOZ_DEFAULT_BROWSER_AGENT)
+#if defined(MOZ_DEFAULT_BROWSER_AGENT)
+static const char kPrefDefaultAgentEnabled[] = "default-browser-agent.enabled";
+
+static const char kPrefServicesSettingsServer[] = "services.settings.server";
+static const char kPrefSecurityContentSignatureRootHash[] =
+    "security.content.signature.root_hash";
+static const char kPrefSetDefaultBrowserUserChoicePref[] =
+    "browser.shell.setDefaultBrowserUserChoice";
+#endif  // defined(MOZ_DEFAULT_BROWSER_AGENT)
+
+#if defined(XP_WIN)
+static const char kPrefThemeId[] = "extensions.activeThemeID";
+static const char kPrefBrowserStartupBlankWindow[] =
+    "browser.startup.blankWindow";
+static const char kPrefPreXulSkeletonUI[] = "browser.startup.preXulSkeletonUI";
+#endif  // defined(XP_WIN)
+
+#if defined(MOZ_WIDGET_GTK)
+constexpr nsLiteralCString kStartupTokenNames[] = {
+    "XDG_ACTIVATION_TOKEN"_ns,
+    "DESKTOP_STARTUP_ID"_ns,
+};
+#endif
+
+int gArgc;
+char** gArgv;
+
+static const char gToolkitVersion[] = MOZ_STRINGIFY(GRE_MILESTONE);
+// The gToolkitBuildID global is defined to MOZ_BUILDID via gen_buildid.py
+// in toolkit/library. See related comment in toolkit/library/moz.build.
+extern const char gToolkitBuildID[];
+
+static nsIProfileLock* gProfileLock;
+#if defined(MOZ_HAS_REMOTE)
+static nsRemoteService* gRemoteService;
+bool gRestartWithoutRemote = false;
+#endif
+
+int gRestartArgc;
+char** gRestartArgv;
+
+// If gRestartedByOS is set, we were automatically restarted by the OS.
+bool gRestartedByOS = false;
+
+bool gIsGtest = false;
+
+nsString gAbsoluteArgv0Path;
+
+#if defined(XP_WIN)
+nsString gProcessStartupShortcut;
+#endif
+
+#if defined(MOZ_WIDGET_GTK)
+#  include <glib.h>
+#  include "mozilla/WidgetUtilsGtk.h"
+#  include <gtk/gtk.h>
+#  ifdef MOZ_WAYLAND
+#    include <gdk/gdkwayland.h>
+#    include "mozilla/widget/nsWaylandDisplay.h"
+#  endif
+#  ifdef MOZ_X11
+#    include <gdk/gdkx.h>
+#  endif /* MOZ_X11 */
+#endif
+#include "BinaryPath.h"
+
+#ifdef MOZ_LINKER
+extern "C" MFBT_API bool IsSignalHandlingBroken();
+#endif
+
+#ifdef FUZZING
+#  include "FuzzerRunner.h"
+
+namespace mozilla {
+FuzzerRunner* fuzzerRunner = 0;
+}  // namespace mozilla
+
+#  ifdef LIBFUZZER
+void XRE_LibFuzzerSetDriver(LibFuzzerDriver aDriver) {
+  mozilla::fuzzerRunner->setParams(aDriver);
+}
+#  endif
+#endif  // FUZZING
+
+// Undo X11/X.h's definition of None
+#undef None
+
+namespace mozilla {
+int (*RunGTest)(int*, char**) = 0;
+
+bool RunningGTest() { return RunGTest; }
+}  // namespace mozilla
+
+using namespace mozilla;
+using namespace mozilla::widget;
+using namespace mozilla::startup;
+using mozilla::Unused;
+using mozilla::dom::ContentChild;
+using mozilla::dom::ContentParent;
+using mozilla::dom::quota::QuotaManager;
+using mozilla::intl::LocaleService;
+using mozilla::scache::StartupCache;
+
+// Save the given word to the specified environment variable.
+static void MOZ_NEVER_INLINE SaveWordToEnv(const char* name,
+                                           const nsACString& word) {
+  char* expr =
+      Smprintf("%s=%s", name, PromiseFlatCString(word).get()).release();
+  if (expr) PR_SetEnv(expr);
+  // We intentionally leak |expr| here since it is required by PR_SetEnv.
+}
+
+// Save the path of the given file to the specified environment variable.
+static void SaveFileToEnv(const char* name, nsIFile* file) {
+#ifdef XP_WIN
+  nsAutoString path;
+  file->GetPath(path);
+  SetEnvironmentVariableW(NS_ConvertASCIItoUTF16(name).get(), path.get());
+#else
+  nsAutoCString path;
+  file->GetNativePath(path);
+  SaveWordToEnv(name, path);
+#endif
+}
+
+static bool gIsExpectedExit = false;
+
+void MozExpectedExit() { gIsExpectedExit = true; }
+
+/**
+ * Runs atexit() to catch unexpected exit from 3rd party libraries like the
+ * Intel graphics driver calling exit in an error condition. When they
+ * call exit() to report an error we won't shutdown correctly and wont catch
+ * the issue with our crash reporter.
+ */
+static void UnexpectedExit() {
+  if (!gIsExpectedExit) {
+    gIsExpectedExit = true;  // Don't risk re-entrency issues when crashing.
+    MOZ_CRASH("Exit called by third party code.");
+  }
+}
+
+#if defined(MOZ_WAYLAND)
+bool IsWaylandEnabled() {
+  static bool isWaylandEnabled = []() {
+    const char* waylandDisplay = PR_GetEnv("WAYLAND_DISPLAY");
+    if (!waylandDisplay) {
+      return false;
+    }
+    if (!PR_GetEnv("DISPLAY")) {
+      // No X11 display, so try to run wayland.
+      return true;
+    }
+    // MOZ_ENABLE_WAYLAND is our primary Wayland on/off switch.
+    if (const char* waylandPref = PR_GetEnv("MOZ_ENABLE_WAYLAND")) {
+      return *waylandPref == '1';
+    }
+    if (const char* backendPref = PR_GetEnv("GDK_BACKEND")) {
+      if (!strncmp(backendPref, "wayland", 7)) {
+        NS_WARNING(
+            "Wayland backend should be enabled by MOZ_ENABLE_WAYLAND=1."
+            "GDK_BACKEND is a Gtk3 debug variable and may cause issues.");
+        return true;
+      }
+    }
+#  ifdef EARLY_BETA_OR_EARLIER
+    // Enable by default when we're running on a recent enough GTK version. We'd
+    // like to check further details like compositor version and so on ideally
+    // to make sure we don't enable it on old Mutter or what not, but we can't,
+    // so let's assume that if the user is running on a Wayland session by
+    // default we're ok, since either the distro has enabled Wayland by default,
+    // or the user has gone out of their way to use Wayland.
+    //
+    // TODO(emilio): If users hit problems, we might be able to restrict it to
+    // GNOME / KDE  / known-good-desktop environments by checking
+    // XDG_CURRENT_DESKTOP or so...
+    return !gtk_check_version(3, 24, 30);
+#  else
+    return false;
+#  endif
+  }();
+  return isWaylandEnabled;
+}
+#else
+bool IsWaylandEnabled() { return false; }
+#endif
+
+/**
+ * Output a string to the user.  This method is really only meant to be used to
+ * output last-ditch error messages designed for developers NOT END USERS.
+ *
+ * @param isError
+ *        Pass true to indicate severe errors.
+ * @param fmt
+ *        printf-style format string followed by arguments.
+ */
+static MOZ_FORMAT_PRINTF(2, 3) void Output(bool isError, const char* fmt, ...) {
+  va_list ap;
+  va_start(ap, fmt);
+
+#if defined(XP_WIN) && !MOZ_WINCONSOLE
+  SmprintfPointer msg = mozilla::Vsmprintf(fmt, ap);
+  if (msg) {
+    UINT flags = MB_OK;
+    if (isError)
+      flags |= MB_ICONERROR;
+    else
+      flags |= MB_ICONINFORMATION;
+
+    wchar_t wide_msg[1024];
+    MultiByteToWideChar(CP_ACP, 0, msg.get(), -1, wide_msg,
+                        sizeof(wide_msg) / sizeof(wchar_t));
+
+    MessageBoxW(nullptr, wide_msg, L"XULRunner", flags);
+  }
+#elif defined(MOZ_WIDGET_ANDROID)
+  SmprintfPointer msg = mozilla::Vsmprintf(fmt, ap);
+  if (msg) {
+    __android_log_print(isError ? ANDROID_LOG_ERROR : ANDROID_LOG_INFO,
+                        "GeckoRuntime", "%s", msg.get());
+  }
+#else
+  vfprintf(stderr, fmt, ap);
+#endif
+
+  va_end(ap);
+}
+
+/**
+ * Check for a commandline flag. If the flag takes a parameter, the
+ * parameter is returned in aParam. Flags may be in the form -arg or
+ * --arg (or /arg on win32).
+ *
+ * @param aArg the parameter to check. Must be lowercase.
+ * @param aParam if non-null, the -arg <data> will be stored in this pointer.
+ *        This is *not* allocated, but rather a pointer to the argv data.
+ * @param aFlags flags @see CheckArgFlag
+ */
+static ArgResult CheckArg(const char* aArg, const char** aParam = nullptr,
+                          CheckArgFlag aFlags = CheckArgFlag::RemoveArg) {
+  MOZ_ASSERT(gArgv, "gArgv must be initialized before CheckArg()");
+  return CheckArg(gArgc, gArgv, aArg, aParam, aFlags);
+}
+
+/**
+ * Check for a commandline flag. Ignore data that's passed in with the flag.
+ * Flags may be in the form -arg or --arg (or /arg on win32).
+ * Will not remove flag if found.
+ *
+ * @param aArg the parameter to check. Must be lowercase.
+ */
+static ArgResult CheckArgExists(const char* aArg) {
+  return CheckArg(aArg, nullptr, CheckArgFlag::None);
+}
+
+bool gSafeMode = false;
+bool gFxREmbedded = false;
+
+enum E10sStatus {
+  kE10sEnabledByDefault,
+  kE10sDisabledByUser,
+  kE10sForceDisabled,
+};
+
+static bool gBrowserTabsRemoteAutostart = false;
+static E10sStatus gBrowserTabsRemoteStatus;
+static bool gBrowserTabsRemoteAutostartInitialized = false;
+
+namespace mozilla {
+
+bool BrowserTabsRemoteAutostart() {
+  if (gBrowserTabsRemoteAutostartInitialized) {
+    return gBrowserTabsRemoteAutostart;
+  }
+  gBrowserTabsRemoteAutostartInitialized = true;
+
+  // If we're not in the parent process, we are running E10s.
+  if (!XRE_IsParentProcess()) {
+    gBrowserTabsRemoteAutostart = true;
+    return gBrowserTabsRemoteAutostart;
+  }
+
+#if defined(MOZILLA_OFFICIAL) && MOZ_BUILD_APP_IS_BROWSER
+  bool allowSingleProcessOutsideAutomation = false;
+#else
+  bool allowSingleProcessOutsideAutomation = true;
+#endif
+
+  E10sStatus status = kE10sEnabledByDefault;
+  // We use "are non-local connections disabled" as a proxy for
+  // "are we running some kind of automated test". It would be nicer to use
+  // xpc::IsInAutomation(), but that depends on some prefs being set, which
+  // they are not in (at least) gtests (where we can't) and xpcshell.
+  // Long-term, hopefully we can make tests switch to environment variables
+  // to disable e10s and then we can get rid of this.
+  if (allowSingleProcessOutsideAutomation ||
+      xpc::AreNonLocalConnectionsDisabled()) {
+    bool optInPref =
+        Preferences::GetBool("browser.tabs.remote.autostart", true);
+
+    if (optInPref) {
+      gBrowserTabsRemoteAutostart = true;
+    } else {
+      status = kE10sDisabledByUser;
+    }
+  } else {
+    gBrowserTabsRemoteAutostart = true;
+  }
+
+  // Uber override pref for emergency blocking
+  if (gBrowserTabsRemoteAutostart) {
+    const char* forceDisable = PR_GetEnv("MOZ_FORCE_DISABLE_E10S");
+#if defined(MOZ_WIDGET_ANDROID)
+    // We need this for xpcshell on Android
+    if (forceDisable && *forceDisable) {
+#else
+    // The environment variable must match the application version to apply.
+    if (forceDisable && gAppData && !strcmp(forceDisable, gAppData->version)) {
+#endif
+      gBrowserTabsRemoteAutostart = false;
+      status = kE10sForceDisabled;
+    }
+  }
+
+  gBrowserTabsRemoteStatus = status;
+
+  return gBrowserTabsRemoteAutostart;
+}
+
+}  // namespace mozilla
+
+// Win32k Infrastructure ==============================================
+
+// This bool tells us if we have initialized the following two statics
+// upon startup.
+
+static bool gWin32kInitialized = false;
+
+// Win32k Lockdown for the current session is determined once, at startup,
+// and then remains the same for the duration of the session.
+
+static nsIXULRuntime::ContentWin32kLockdownState gWin32kStatus;
+
+// The status of the win32k experiment. It is determined once, at startup,
+// and then remains the same for the duration of the session.
+
+static nsIXULRuntime::ExperimentStatus gWin32kExperimentStatus =
+    nsIXULRuntime::eExperimentStatusUnenrolled;
+
+#ifdef XP_WIN
+// The states for win32k lockdown can be generalized to:
+//  - User doesn't meet requirements (bad OS, webrender, remotegl) aka
+//  PersistentRequirement
+//  - User has Safe Mode enabled, Win32k Disabled by Env Var, or E10S disabled
+//  by Env Var aka TemporaryRequirement
+//  - User has set the win32k pref to something non-default aka NonDefaultPref
+//  - User has been enrolled in the experiment and does what it says aka
+//  Enrolled
+//  - User does the default aka Default
+//
+// We expect the below behvaior.  In the code, there may be references to these
+//     behaviors (e.g. [A]) but not always.
+//
+// [A] Becoming enrolled in the experiment while NonDefaultPref disqualifies
+//     you upon next browser start
+// [B] Becoming enrolled in the experiment while PersistentRequirement
+//     disqualifies you upon next browser start
+// [C] Becoming enrolled in the experiment while TemporaryRequirement does not
+//     disqualify you
+// [D] Becoming enrolled in the experiment will only take effect after restart
+// [E] While enrolled, becoming PersistentRequirement will not disqualify you
+//     until browser restart, but if the state is present at browser start,
+//     will disqualify you. Additionally, it will not affect the session value
+//     of gWin32kStatus.
+//     XXX(bobowen): I hope both webrender and wbgl.out-of-process require a
+//                   restart to take effect!
+// [F] While enrolled, becoming NonDefaultPref will disqualify you upon next
+//     browser start
+// [G] While enrolled, becoming TemporaryRequirement will _not_ disqualify you,
+//     but the session status will prevent win32k lockdown from taking effect.
+
+// The win32k pref
+static const char kPrefWin32k[] = "security.sandbox.content.win32k-disable";
+
+// The current enrollment status as controlled by Normandy. This value is only
+// stored in the default preference branch, and is not persisted across
+// sessions by the preference service. It therefore isn't available early
+// enough at startup, and needs to be synced to a preference in the user
+// branch which is persisted across sessions.
+static const char kPrefWin32kExperimentEnrollmentStatus[] =
+    "security.sandbox.content.win32k-experiment.enrollmentStatus";
+
+// The enrollment status to be used at browser startup. This automatically
+// synced from the above enrollmentStatus preference whenever the latter is
+// changed. We reused the Fission experiment enum - it can have any of the
+// values defined in the `nsIXULRuntime_ExperimentStatus` enum _except_ rollout.
+// Meanings are documented in the declaration of
+// `nsIXULRuntime.fissionExperimentStatus`
+static const char kPrefWin32kExperimentStartupEnrollmentStatus[] =
+    "security.sandbox.content.win32k-experiment.startupEnrollmentStatus";
+
+namespace mozilla {
+
+bool Win32kExperimentEnrolled() {
+  MOZ_ASSERT(XRE_IsParentProcess());
+  return gWin32kExperimentStatus == nsIXULRuntime::eExperimentStatusControl ||
+         gWin32kExperimentStatus == nsIXULRuntime::eExperimentStatusTreatment;
+}
+
+}  // namespace mozilla
+
+static bool Win32kRequirementsUnsatisfied(
+    nsIXULRuntime::ContentWin32kLockdownState aStatus) {
+  return aStatus == nsIXULRuntime::ContentWin32kLockdownState::
+                        OperatingSystemNotSupported ||
+         aStatus ==
+             nsIXULRuntime::ContentWin32kLockdownState::MissingWebRender ||
+         aStatus ==
+             nsIXULRuntime::ContentWin32kLockdownState::MissingRemoteWebGL ||
+         aStatus ==
+             nsIXULRuntime::ContentWin32kLockdownState::DecodersArentRemote;
+}
+
+static void Win32kExperimentDisqualify() {
+  MOZ_ASSERT(XRE_IsParentProcess());
+  Preferences::SetUint(kPrefWin32kExperimentEnrollmentStatus,
+                       nsIXULRuntime::eExperimentStatusDisqualified);
+}
+
+static void OnWin32kEnrollmentStatusChanged(const char* aPref, void* aData) {
+  auto newStatusInt =
+      Preferences::GetUint(kPrefWin32kExperimentEnrollmentStatus,
+                           nsIXULRuntime::eExperimentStatusUnenrolled);
+  auto newStatus = newStatusInt < nsIXULRuntime::eExperimentStatusCount
+                       ? nsIXULRuntime::ExperimentStatus(newStatusInt)
+                       : nsIXULRuntime::eExperimentStatusDisqualified;
+
+  // Set the startup pref for next browser start [D]
+  Preferences::SetUint(kPrefWin32kExperimentStartupEnrollmentStatus, newStatus);
+}
+
+namespace {
+// This observer is notified during `profile-before-change`, and ensures that
+// the experiment enrollment status is synced over before the browser shuts
+// down, even if it was not modified since win32k was initialized.
+class Win32kEnrollmentStatusShutdownObserver final : public nsIObserver {
+ public:
+  NS_DECL_ISUPPORTS
+
+  NS_IMETHOD Observe(nsISupports* aSubject, const char* aTopic,
+                     const char16_t* aData) override {
+    MOZ_ASSERT(!strcmp("profile-before-change", aTopic));
+    OnWin32kEnrollmentStatusChanged(kPrefWin32kExperimentEnrollmentStatus,
+                                    nullptr);
+    return NS_OK;
+  }
+
+ private:
+  ~Win32kEnrollmentStatusShutdownObserver() = default;
+};
+NS_IMPL_ISUPPORTS(Win32kEnrollmentStatusShutdownObserver, nsIObserver)
+}  // namespace
+
+static void OnWin32kChanged(const char* aPref, void* aData) {
+  // If we're actively enrolled in the Win32k experiment, disqualify the user
+  // from the experiment if the Win32k pref is modified. [F]
+  if (Win32kExperimentEnrolled() && Preferences::HasUserValue(kPrefWin32k)) {
+    Win32kExperimentDisqualify();
+  }
+}
+
+#endif  // XP_WIN
+
+namespace mozilla {
+void EnsureWin32kInitialized();
+}
+
+nsIXULRuntime::ContentWin32kLockdownState GetLiveWin32kLockdownState() {
+#ifdef XP_WIN
+
+  // HasUserValue The Pref functions can only be called on main thread
+  MOZ_ASSERT(NS_IsMainThread());
+
+#  ifdef MOZ_BACKGROUNDTASKS
+  if (BackgroundTasks::IsBackgroundTaskMode()) {
+    // Let's bail out before loading all the graphics libs.
+    return nsIXULRuntime::ContentWin32kLockdownState::DisabledByDefault;
+  }
+#  endif
+
+  mozilla::EnsureWin32kInitialized();
+  gfxPlatform::GetPlatform();
+
+  if (gSafeMode) {
+    return nsIXULRuntime::ContentWin32kLockdownState::DisabledBySafeMode;
+  }
+
+  if (EnvHasValue("MOZ_ENABLE_WIN32K")) {
+    return nsIXULRuntime::ContentWin32kLockdownState::DisabledByEnvVar;
+  }
+
+  if (!mozilla::BrowserTabsRemoteAutostart()) {
+    return nsIXULRuntime::ContentWin32kLockdownState::DisabledByE10S;
+  }
+
+  // Win32k lockdown is available on Win8+, but we are initially limiting it to
+  // Windows 10 v1709 (build 16299) or later. Before this COM initialization
+  // currently fails if user32.dll has loaded before it is called.
+  if (!IsWin10FallCreatorsUpdateOrLater()) {
+    return nsIXULRuntime::ContentWin32kLockdownState::
+        OperatingSystemNotSupported;
+  }
+
+  {
+    ConflictingMitigationStatus conflictingMitigationStatus = {};
+    if (!detect_win32k_conflicting_mitigations(&conflictingMitigationStatus)) {
+      return nsIXULRuntime::ContentWin32kLockdownState::
+          IncompatibleMitigationPolicy;
+    }
+    if (conflictingMitigationStatus.caller_check ||
+        conflictingMitigationStatus.sim_exec ||
+        conflictingMitigationStatus.stack_pivot) {
+      return nsIXULRuntime::ContentWin32kLockdownState::
+          IncompatibleMitigationPolicy;
+    }
+  }
+
+  // Non-native theming is required as well
+  if (!StaticPrefs::widget_non_native_theme_enabled()) {
+    return nsIXULRuntime::ContentWin32kLockdownState::MissingNonNativeTheming;
+  }
+
+  // Win32k Lockdown requires Remote WebGL, but it may be disabled on
+  // certain hardware or virtual machines.
+  if (!gfx::gfxVars::AllowWebglOop() || !StaticPrefs::webgl_out_of_process()) {
+    return nsIXULRuntime::ContentWin32kLockdownState::MissingRemoteWebGL;
+  }
+
+  // Some (not sure exactly which) decoders are not compatible
+  if (!PDMFactory::AllDecodersAreRemote()) {
+    return nsIXULRuntime::ContentWin32kLockdownState::DecodersArentRemote;
+  }
+
+  bool prefSetByUser =
+      Preferences::HasUserValue("security.sandbox.content.win32k-disable");
+  bool prefValue = Preferences::GetBool(
+      "security.sandbox.content.win32k-disable", false, PrefValueKind::User);
+  bool defaultValue = Preferences::GetBool(
+      "security.sandbox.content.win32k-disable", false, PrefValueKind::Default);
+
+  if (prefSetByUser) {
+    if (prefValue) {
+      return nsIXULRuntime::ContentWin32kLockdownState::EnabledByUserPref;
+    } else {
+      return nsIXULRuntime::ContentWin32kLockdownState::DisabledByUserPref;
+    }
+  }
+
+  if (gWin32kExperimentStatus ==
+      nsIXULRuntime::ExperimentStatus::eExperimentStatusControl) {
+    return nsIXULRuntime::ContentWin32kLockdownState::DisabledByControlGroup;
+  } else if (gWin32kExperimentStatus ==
+             nsIXULRuntime::ExperimentStatus::eExperimentStatusTreatment) {
+    return nsIXULRuntime::ContentWin32kLockdownState::EnabledByTreatmentGroup;
+  }
+
+  if (defaultValue) {
+    return nsIXULRuntime::ContentWin32kLockdownState::EnabledByDefault;
+  } else {
+    return nsIXULRuntime::ContentWin32kLockdownState::DisabledByDefault;
+  }
+
+#else
+
+  return nsIXULRuntime::ContentWin32kLockdownState::OperatingSystemNotSupported;
+
+#endif
+}
+
+namespace mozilla {
+
+void EnsureWin32kInitialized() {
+  if (gWin32kInitialized) {
+    return;
+  }
+  gWin32kInitialized = true;
+
+#ifdef XP_WIN
+
+  // Initialize the Win32k experiment, configuring win32k's
+  // default, before checking other overrides. This allows opting-out of a
+  // Win32k experiment through about:preferences or about:config from a
+  // safemode session.
+  uint32_t experimentRaw =
+      Preferences::GetUint(kPrefWin32kExperimentStartupEnrollmentStatus,
+                           nsIXULRuntime::eExperimentStatusUnenrolled);
+  gWin32kExperimentStatus =
+      experimentRaw < nsIXULRuntime::eExperimentStatusCount
+          ? nsIXULRuntime::ExperimentStatus(experimentRaw)
+          : nsIXULRuntime::eExperimentStatusDisqualified;
+
+  // Watch the experiment enrollment status pref to detect experiment
+  // disqualification, and ensure it is propagated for the next restart.
+  Preferences::RegisterCallback(&OnWin32kEnrollmentStatusChanged,
+                                kPrefWin32kExperimentEnrollmentStatus);
+  if (nsCOMPtr<nsIObserverService> observerService =
+          mozilla::services::GetObserverService()) {
+    nsCOMPtr<nsIObserver> shutdownObserver =
+        new Win32kEnrollmentStatusShutdownObserver();
+    observerService->AddObserver(shutdownObserver, "profile-before-change",
+                                 false);
+  }
+
+  // If the user no longer qualifies because they edited a required pref, check
+  // that. [B] [E]
+  auto tmpStatus = GetLiveWin32kLockdownState();
+  if (Win32kExperimentEnrolled() && Win32kRequirementsUnsatisfied(tmpStatus)) {
+    Win32kExperimentDisqualify();
+    gWin32kExperimentStatus = nsIXULRuntime::eExperimentStatusDisqualified;
+  }
+
+  // If the user has overridden an active experiment by setting a user value for
+  // "security.sandbox.content.win32k-disable", disqualify the user from the
+  // experiment. [A] [F]
+  if (Preferences::HasUserValue(kPrefWin32k) && Win32kExperimentEnrolled()) {
+    Win32kExperimentDisqualify();
+    gWin32kExperimentStatus = nsIXULRuntime::eExperimentStatusDisqualified;
+  }
+
+  // Unlike Fission, we do not configure the default branch based on experiment
+  // enrollment status.  Instead we check the startupEnrollmentPref in
+  // GetContentWin32kLockdownState()
+
+  Preferences::RegisterCallback(&OnWin32kChanged, kPrefWin32k);
+
+  // Set the state
+  gWin32kStatus = GetLiveWin32kLockdownState();
+
+#else
+  gWin32kStatus =
+      nsIXULRuntime::ContentWin32kLockdownState::OperatingSystemNotSupported;
+  gWin32kExperimentStatus = nsIXULRuntime::eExperimentStatusUnenrolled;
+
+#endif  // XP_WIN
+}
+
+nsIXULRuntime::ContentWin32kLockdownState GetWin32kLockdownState() {
+#ifdef XP_WIN
+
+  mozilla::EnsureWin32kInitialized();
+  return gWin32kStatus;
+
+#else
+
+  return nsIXULRuntime::ContentWin32kLockdownState::OperatingSystemNotSupported;
+
+#endif
+}
+
+}  // namespace mozilla
+
+// End Win32k Infrastructure ==========================================
+
+// Fission Infrastructure =============================================
+
+// Fission enablement for the current session is determined once, at startup,
+// and then remains the same for the duration of the session.
+//
+// The following factors determine whether or not Fission is enabled for a
+// session, in order of precedence:
+//
+// - Safe mode: In safe mode, Fission is never enabled.
+//
+// - The MOZ_FORCE_ENABLE_FISSION environment variable: If set to any value,
+//   Fission will be enabled.
+//
+// - The 'fission.autostart' preference, if it has been configured by the user.
+static const char kPrefFissionAutostart[] = "fission.autostart";
+
+// The computed FissionAutostart value for the session, read by content
+// processes to initialize gFissionAutostart.
+//
+// This pref is locked, and only configured on the default branch, so should
+// never be persisted in a profile.
+static const char kPrefFissionAutostartSession[] = "fission.autostart.session";
+
+//
+// The computed FissionAutostart value for the session, read by content
+// processes to initialize gFissionAutostart.
+
+static bool gFissionAutostart = false;
+static bool gFissionAutostartInitialized = false;
+static nsIXULRuntime::FissionDecisionStatus gFissionDecisionStatus;
+static void EnsureFissionAutostartInitialized() {
+  if (gFissionAutostartInitialized) {
+    return;
+  }
+  gFissionAutostartInitialized = true;
+
+  if (!XRE_IsParentProcess()) {
+    // This pref is configured for the current session by the parent process.
+    gFissionAutostart = Preferences::GetBool(kPrefFissionAutostartSession,
+                                             false, PrefValueKind::Default);
+    return;
+  }
+
+  if (!BrowserTabsRemoteAutostart()) {
+    gFissionAutostart = false;
+    if (gBrowserTabsRemoteStatus == kE10sForceDisabled) {
+      gFissionDecisionStatus = nsIXULRuntime::eFissionDisabledByE10sEnv;
+    } else {
+      gFissionDecisionStatus = nsIXULRuntime::eFissionDisabledByE10sOther;
+    }
+  } else if (EnvHasValue("MOZ_FORCE_ENABLE_FISSION")) {
+    gFissionAutostart = true;
+    gFissionDecisionStatus = nsIXULRuntime::eFissionEnabledByEnv;
+  } else if (EnvHasValue("MOZ_FORCE_DISABLE_FISSION")) {
+    gFissionAutostart = false;
+    gFissionDecisionStatus = nsIXULRuntime::eFissionDisabledByEnv;
+  } else {
+    // NOTE: This will take into account changes to the default due to
+    // `InitializeFissionExperimentStatus`.
+    gFissionAutostart = Preferences::GetBool(kPrefFissionAutostart, false);
+    if (Preferences::HasUserValue(kPrefFissionAutostart)) {
+      gFissionDecisionStatus = gFissionAutostart
+                                   ? nsIXULRuntime::eFissionEnabledByUserPref
+                                   : nsIXULRuntime::eFissionDisabledByUserPref;
+    } else {
+      gFissionDecisionStatus = gFissionAutostart
+                                   ? nsIXULRuntime::eFissionEnabledByDefault
+                                   : nsIXULRuntime::eFissionDisabledByDefault;
+    }
+  }
+
+  // Content processes cannot run the same logic as we're running in the parent
+  // process, as the current value of various preferences may have changed
+  // between launches. Instead, the content process will read the default branch
+  // of the locked `fission.autostart.session` preference to determine the value
+  // determined by this method.
+  Preferences::Unlock(kPrefFissionAutostartSession);
+  Preferences::ClearUser(kPrefFissionAutostartSession);
+  Preferences::SetBool(kPrefFissionAutostartSession, gFissionAutostart,
+                       PrefValueKind::Default);
+  Preferences::Lock(kPrefFissionAutostartSession);
+}
+
+namespace mozilla {
+
+bool FissionAutostart() {
+  EnsureFissionAutostartInitialized();
+  return gFissionAutostart;
+}
+
+}  // namespace mozilla
+
+// End Fission Infrastructure =========================================
+
+namespace mozilla {
+
+bool SessionHistoryInParent() {
+  return FissionAutostart() ||
+         !StaticPrefs::
+             fission_disableSessionHistoryInParent_AtStartup_DoNotUseDirectly();
+}
+
+bool BFCacheInParent() {
+  return SessionHistoryInParent() &&
+         StaticPrefs::fission_bfcacheInParent_DoNotUseDirectly();
+}
+
+}  // namespace mozilla
+
+/**
+ * The nsXULAppInfo object implements nsIFactory so that it can be its own
+ * singleton.
+ */
+class nsXULAppInfo : public nsIXULAppInfo,
+#ifdef XP_WIN
+                     public nsIWinAppHelper,
+#endif
+                     public nsICrashReporter,
+                     public nsIFinishDumpingCallback,
+                     public nsIXULRuntime
+
+{
+ public:
+  constexpr nsXULAppInfo() = default;
+  NS_DECL_ISUPPORTS_INHERITED
+  NS_DECL_NSIPLATFORMINFO
+  NS_DECL_NSIXULAPPINFO
+  NS_DECL_NSIXULRUNTIME
+  NS_DECL_NSICRASHREPORTER
+  NS_DECL_NSIFINISHDUMPINGCALLBACK
+#ifdef XP_WIN
+  NS_DECL_NSIWINAPPHELPER
+#endif
+};
+
+NS_INTERFACE_MAP_BEGIN(nsXULAppInfo)
+  NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIXULRuntime)
+  NS_INTERFACE_MAP_ENTRY(nsIXULRuntime)
+#ifdef XP_WIN
+  NS_INTERFACE_MAP_ENTRY(nsIWinAppHelper)
+#endif
+  NS_INTERFACE_MAP_ENTRY(nsICrashReporter)
+  NS_INTERFACE_MAP_ENTRY(nsIFinishDumpingCallback)
+  NS_INTERFACE_MAP_ENTRY(nsIPlatformInfo)
+  NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIXULAppInfo,
+                                     gAppData || XRE_IsContentProcess())
+NS_INTERFACE_MAP_END
+
+NS_IMETHODIMP_(MozExternalRefCountType)
+nsXULAppInfo::AddRef() { return 1; }
+
+NS_IMETHODIMP_(MozExternalRefCountType)
+nsXULAppInfo::Release() { return 1; }
+
+NS_IMETHODIMP
+nsXULAppInfo::GetVendor(nsACString& aResult) {
+  if (XRE_IsContentProcess()) {
+    ContentChild* cc = ContentChild::GetSingleton();
+    aResult = cc->GetAppInfo().vendor;
+    return NS_OK;
+  }
+  aResult.Assign(gAppData->vendor);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetName(nsACString& aResult) {
+  if (XRE_IsContentProcess()) {
+    ContentChild* cc = ContentChild::GetSingleton();
+    aResult = cc->GetAppInfo().name;
+    return NS_OK;
+  }
+
+#ifdef MOZ_WIDGET_ANDROID
+  nsCString name = java::GeckoAppShell::GetAppName()->ToCString();
+  aResult.Assign(std::move(name));
+#else
+  aResult.Assign(gAppData->name);
+#endif
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetID(nsACString& aResult) {
+  if (XRE_IsContentProcess()) {
+    ContentChild* cc = ContentChild::GetSingleton();
+    aResult = cc->GetAppInfo().ID;
+    return NS_OK;
+  }
+  aResult.Assign(gAppData->ID);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetVersion(nsACString& aResult) {
+  if (XRE_IsContentProcess()) {
+    ContentChild* cc = ContentChild::GetSingleton();
+    aResult = cc->GetAppInfo().version;
+    return NS_OK;
+  }
+  aResult.Assign(gAppData->version);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetPlatformVersion(nsACString& aResult) {
+  aResult.Assign(gToolkitVersion);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetAppBuildID(nsACString& aResult) {
+  if (XRE_IsContentProcess()) {
+    ContentChild* cc = ContentChild::GetSingleton();
+    aResult = cc->GetAppInfo().buildID;
+    return NS_OK;
+  }
+  aResult.Assign(gAppData->buildID);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetPlatformBuildID(nsACString& aResult) {
+  aResult.Assign(gToolkitBuildID);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetUAName(nsACString& aResult) {
+  if (XRE_IsContentProcess()) {
+    ContentChild* cc = ContentChild::GetSingleton();
+    aResult = cc->GetAppInfo().UAName;
+    return NS_OK;
+  }
+  aResult.Assign(gAppData->UAName);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetSourceURL(nsACString& aResult) {
+  if (XRE_IsContentProcess()) {
+    ContentChild* cc = ContentChild::GetSingleton();
+    aResult = cc->GetAppInfo().sourceURL;
+    return NS_OK;
+  }
+  aResult.Assign(gAppData->sourceURL);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetUpdateURL(nsACString& aResult) {
+  if (XRE_IsContentProcess()) {
+    ContentChild* cc = ContentChild::GetSingleton();
+    aResult = cc->GetAppInfo().updateURL;
+    return NS_OK;
+  }
+  aResult.Assign(gAppData->updateURL);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetLogConsoleErrors(bool* aResult) {
+  *aResult = gLogConsoleErrors;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::SetLogConsoleErrors(bool aValue) {
+  gLogConsoleErrors = aValue;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetInSafeMode(bool* aResult) {
+  *aResult = gSafeMode;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetOS(nsACString& aResult) {
+  aResult.AssignLiteral(OS_TARGET);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetXPCOMABI(nsACString& aResult) {
+#ifdef TARGET_XPCOM_ABI
+  aResult.AssignLiteral(TARGET_XPCOM_ABI);
+  return NS_OK;
+#else
+  return NS_ERROR_NOT_AVAILABLE;
+#endif
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetWidgetToolkit(nsACString& aResult) {
+  aResult.AssignLiteral(MOZ_WIDGET_TOOLKIT);
+  return NS_OK;
+}
+
+// Ensure that the GeckoProcessType enum, defined in xpcom/build/nsXULAppAPI.h,
+// is synchronized with the const unsigned longs defined in
+// xpcom/system/nsIXULRuntime.idl.
+#define GECKO_PROCESS_TYPE(enum_value, enum_name, string_name, proc_typename, \
+                           process_bin_type, procinfo_typename,               \
+                           webidl_typename, allcaps_name)                     \
+  static_assert(nsIXULRuntime::PROCESS_TYPE_##allcaps_name ==                 \
+                    static_cast<int>(GeckoProcessType_##enum_name),           \
+                "GeckoProcessType in nsXULAppAPI.h not synchronized with "    \
+                "nsIXULRuntime.idl");
+#include "mozilla/GeckoProcessTypes.h"
+#undef GECKO_PROCESS_TYPE
+
+// .. and ensure that that is all of them:
+static_assert(GeckoProcessType_Utility + 1 == GeckoProcessType_End,
+              "Did not find the final GeckoProcessType");
+
+NS_IMETHODIMP
+nsXULAppInfo::GetProcessType(uint32_t* aResult) {
+  NS_ENSURE_ARG_POINTER(aResult);
+  *aResult = XRE_GetProcessType();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetProcessID(uint32_t* aResult) {
+#ifdef XP_WIN
+  *aResult = GetCurrentProcessId();
+#else
+  *aResult = getpid();
+#endif
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetUniqueProcessID(uint64_t* aResult) {
+  if (XRE_IsContentProcess()) {
+    ContentChild* cc = ContentChild::GetSingleton();
+    *aResult = cc->GetID();
+  } else {
+    *aResult = 0;
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetRemoteType(nsACString& aRemoteType) {
+  if (XRE_IsContentProcess()) {
+    aRemoteType = ContentChild::GetSingleton()->GetRemoteType();
+  } else {
+    aRemoteType = NOT_REMOTE_TYPE;
+  }
+
+  return NS_OK;
+}
+
+static nsCString gLastAppVersion;
+static nsCString gLastAppBuildID;
+
+NS_IMETHODIMP
+nsXULAppInfo::GetLastAppVersion(nsACString& aResult) {
+  if (XRE_IsContentProcess()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  if (!gLastAppVersion.IsVoid() && gLastAppVersion.IsEmpty()) {
+    NS_WARNING("Attempt to retrieve lastAppVersion before it has been set.");
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  aResult.Assign(gLastAppVersion);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetLastAppBuildID(nsACString& aResult) {
+  if (XRE_IsContentProcess()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  if (!gLastAppBuildID.IsVoid() && gLastAppBuildID.IsEmpty()) {
+    NS_WARNING("Attempt to retrieve lastAppBuildID before it has been set.");
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  aResult.Assign(gLastAppBuildID);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetFissionAutostart(bool* aResult) {
+  *aResult = FissionAutostart();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetWin32kExperimentStatus(ExperimentStatus* aResult) {
+  if (!XRE_IsParentProcess()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  EnsureWin32kInitialized();
+  *aResult = gWin32kExperimentStatus;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetWin32kLiveStatusTestingOnly(
+    nsIXULRuntime::ContentWin32kLockdownState* aResult) {
+  if (!XRE_IsParentProcess()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  EnsureWin32kInitialized();
+  *aResult = GetLiveWin32kLockdownState();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetWin32kSessionStatus(
+    nsIXULRuntime::ContentWin32kLockdownState* aResult) {
+  if (!XRE_IsParentProcess()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  EnsureWin32kInitialized();
+  *aResult = gWin32kStatus;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetFissionDecisionStatus(FissionDecisionStatus* aResult) {
+  if (!XRE_IsParentProcess()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  EnsureFissionAutostartInitialized();
+
+  MOZ_ASSERT(gFissionDecisionStatus != eFissionStatusUnknown);
+  *aResult = gFissionDecisionStatus;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetFissionDecisionStatusString(nsACString& aResult) {
+  if (!XRE_IsParentProcess()) {
+    return NS_ERROR_NOT_AVAILABLE;
+  }
+
+  EnsureFissionAutostartInitialized();
+  switch (gFissionDecisionStatus) {
+    case eFissionExperimentControl:
+      aResult = "experimentControl";
+      break;
+    case eFissionExperimentTreatment:
+      aResult = "experimentTreatment";
+      break;
+    case eFissionDisabledByE10sEnv:
+      aResult = "disabledByE10sEnv";
+      break;
+    case eFissionEnabledByEnv:
+      aResult = "enabledByEnv";
+      break;
+    case eFissionDisabledByEnv:
+      aResult = "disabledByEnv";
+      break;
+    case eFissionEnabledByDefault:
+      aResult = "enabledByDefault";
+      break;
+    case eFissionDisabledByDefault:
+      aResult = "disabledByDefault";
+      break;
+    case eFissionEnabledByUserPref:
+      aResult = "enabledByUserPref";
+      break;
+    case eFissionDisabledByUserPref:
+      aResult = "disabledByUserPref";
+      break;
+    case eFissionDisabledByE10sOther:
+      aResult = "disabledByE10sOther";
+      break;
+    case eFissionEnabledByRollout:
+      aResult = "enabledByRollout";
+      break;
+    default:
+      MOZ_ASSERT_UNREACHABLE("Unexpected enum value");
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetSessionHistoryInParent(bool* aResult) {
+  *aResult = SessionHistoryInParent();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetBrowserTabsRemoteAutostart(bool* aResult) {
+  *aResult = BrowserTabsRemoteAutostart();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetMaxWebProcessCount(uint32_t* aResult) {
+  *aResult = mozilla::GetMaxWebProcessCount();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetAccessibilityEnabled(bool* aResult) {
+#ifdef ACCESSIBILITY
+  *aResult = GetAccService() != nullptr;
+#else
+  *aResult = false;
+#endif
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetAccessibilityInstantiator(nsAString& aInstantiator) {
+#if defined(ACCESSIBILITY) && defined(XP_WIN)
+  if (!GetAccService()) {
+    aInstantiator.Truncate();
+    return NS_OK;
+  }
+  nsAutoString ipClientInfo;
+  a11y::Compatibility::GetHumanReadableConsumersStr(ipClientInfo);
+  aInstantiator.Append(ipClientInfo);
+  aInstantiator.AppendLiteral("|");
+
+  nsCOMPtr<nsIFile> oopClientExe;
+  if (a11y::GetInstantiator(getter_AddRefs(oopClientExe))) {
+    nsAutoString oopClientInfo;
+    if (NS_SUCCEEDED(oopClientExe->GetPath(oopClientInfo))) {
+      aInstantiator.Append(oopClientInfo);
+    }
+  }
+#else
+  aInstantiator.Truncate();
+#endif
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetShouldBlockIncompatJaws(bool* aResult) {
+  *aResult = false;
+#if defined(ACCESSIBILITY) && defined(XP_WIN)
+  *aResult = mozilla::a11y::Compatibility::IsOldJAWS();
+#endif
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetIs64Bit(bool* aResult) {
+#ifdef HAVE_64BIT_BUILD
+  *aResult = true;
+#else
+  *aResult = false;
+#endif
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetIsTextRecognitionSupported(bool* aResult) {
+  *aResult = widget::TextRecognition::IsSupported();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::EnsureContentProcess() {
+  if (!XRE_IsParentProcess()) return NS_ERROR_NOT_AVAILABLE;
+
+  RefPtr<ContentParent> unused =
+      ContentParent::GetNewOrUsedBrowserProcess(DEFAULT_REMOTE_TYPE);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::InvalidateCachesOnRestart() {
+  nsCOMPtr<nsIFile> file;
+  nsresult rv =
+      NS_GetSpecialDirectory(NS_APP_PROFILE_DIR_STARTUP, getter_AddRefs(file));
+  if (NS_FAILED(rv)) return rv;
+  if (!file) return NS_ERROR_NOT_AVAILABLE;
+
+  file->AppendNative(FILE_COMPATIBILITY_INFO);
+
+  nsINIParser parser;
+  rv = parser.Init(file);
+  if (NS_FAILED(rv)) {
+    // This fails if compatibility.ini is not there, so we'll
+    // flush the caches on the next restart anyways.
+    return NS_OK;
+  }
+
+  nsAutoCString buf;
+  rv = parser.GetString("Compatibility", "InvalidateCaches", buf);
+
+  if (NS_FAILED(rv)) {
+    PRFileDesc* fd;
+    rv = file->OpenNSPRFileDesc(PR_RDWR | PR_APPEND, 0600, &fd);
+    if (NS_FAILED(rv)) {
+      NS_ERROR("could not create output stream");
+      return NS_ERROR_NOT_AVAILABLE;
+    }
+    static const char kInvalidationHeader[] =
+        NS_LINEBREAK "InvalidateCaches=1" NS_LINEBREAK;
+    PR_Write(fd, kInvalidationHeader, sizeof(kInvalidationHeader) - 1);
+    PR_Close(fd);
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetReplacedLockTime(PRTime* aReplacedLockTime) {
+  if (!gProfileLock) return NS_ERROR_NOT_AVAILABLE;
+  gProfileLock->GetReplacedLockTime(aReplacedLockTime);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetDefaultUpdateChannel(nsACString& aResult) {
+  aResult.AssignLiteral(MOZ_STRINGIFY(MOZ_UPDATE_CHANNEL));
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetDistributionID(nsACString& aResult) {
+  aResult.AssignLiteral(MOZ_DISTRIBUTION_ID);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetWindowsDLLBlocklistStatus(bool* aResult) {
+#if defined(HAS_DLL_BLOCKLIST)
+  *aResult = DllBlocklist_CheckStatus();
+#else
+  *aResult = false;
+#endif
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetRestartedByOS(bool* aResult) {
+  *aResult = gRestartedByOS;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetChromeColorSchemeIsDark(bool* aResult) {
+  LookAndFeel::EnsureColorSchemesInitialized();
+  *aResult = LookAndFeel::ColorSchemeForChrome() == ColorScheme::Dark;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetContentThemeDerivedColorSchemeIsDark(bool* aResult) {
+  *aResult =
+      LookAndFeel::ThemeDerivedColorSchemeForContent() == ColorScheme::Dark;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetPrefersReducedMotion(bool* aResult) {
+  *aResult =
+      LookAndFeel::GetInt(LookAndFeel::IntID::PrefersReducedMotion, 0) == 1;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetDrawInTitlebar(bool* aResult) {
+  *aResult = LookAndFeel::DrawInTitlebar();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetDesktopEnvironment(nsACString& aDesktopEnvironment) {
+#ifdef MOZ_WIDGET_GTK
+  aDesktopEnvironment.Assign(GetDesktopEnvironmentIdentifier());
+#endif
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetProcessStartupShortcut(nsAString& aShortcut) {
+#if defined(XP_WIN)
+  if (XRE_IsParentProcess()) {
+    aShortcut.Assign(gProcessStartupShortcut);
+    return NS_OK;
+  }
+#endif
+  return NS_ERROR_NOT_AVAILABLE;
+}
+
+#if defined(XP_WIN) && defined(MOZ_LAUNCHER_PROCESS)
+// Forward declaration
+void SetupLauncherProcessPref();
+
+static Maybe<LauncherRegistryInfo::EnabledState> gLauncherProcessState;
+#endif  // defined(XP_WIN) && defined(MOZ_LAUNCHER_PROCESS)
+
+NS_IMETHODIMP
+nsXULAppInfo::GetLauncherProcessState(uint32_t* aResult) {
+#if defined(XP_WIN) && defined(MOZ_LAUNCHER_PROCESS)
+  SetupLauncherProcessPref();
+
+  if (!gLauncherProcessState) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  *aResult = static_cast<uint32_t>(gLauncherProcessState.value());
+  return NS_OK;
+#else
+  return NS_ERROR_NOT_AVAILABLE;
+#endif
+}
+
+#ifdef XP_WIN
+NS_IMETHODIMP
+nsXULAppInfo::GetUserCanElevate(bool* aUserCanElevate) {
+  HANDLE rawToken;
+  if (!::OpenProcessToken(::GetCurrentProcess(), TOKEN_QUERY, &rawToken)) {
+    *aUserCanElevate = false;
+    return NS_OK;
+  }
+
+  nsAutoHandle token(rawToken);
+  LauncherResult<TOKEN_ELEVATION_TYPE> elevationType = GetElevationType(token);
+  if (elevationType.isErr()) {
+    *aUserCanElevate = false;
+    return NS_OK;
+  }
+
+  // The possible values returned for elevationType and their meanings are:
+  //   TokenElevationTypeDefault: The token does not have a linked token
+  //     (e.g. UAC disabled or a standard user, so they can't be elevated)
+  //   TokenElevationTypeFull: The token is linked to an elevated token
+  //     (e.g. UAC is enabled and the user is already elevated so they can't
+  //      be elevated again)
+  //   TokenElevationTypeLimited: The token is linked to a limited token
+  //     (e.g. UAC is enabled and the user is not elevated, so they can be
+  //      elevated)
+  *aUserCanElevate = (elevationType.inspect() == TokenElevationTypeLimited);
+  return NS_OK;
+}
+#endif
+
+NS_IMETHODIMP
+nsXULAppInfo::GetCrashReporterEnabled(bool* aEnabled) {
+  *aEnabled = CrashReporter::GetEnabled();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::SetEnabled(bool aEnabled) {
+  if (aEnabled) {
+    if (CrashReporter::GetEnabled()) {
+      // no point in erroring for double-enabling
+      return NS_OK;
+    }
+
+    nsCOMPtr<nsIFile> greBinDir;
+    NS_GetSpecialDirectory(NS_GRE_BIN_DIR, getter_AddRefs(greBinDir));
+    if (!greBinDir) {
+      return NS_ERROR_FAILURE;
+    }
+
+    nsCOMPtr<nsIFile> xreBinDirectory = greBinDir;
+    if (!xreBinDirectory) {
+      return NS_ERROR_FAILURE;
+    }
+
+    return CrashReporter::SetExceptionHandler(xreBinDirectory, true);
+  }
+
+  if (!CrashReporter::GetEnabled()) {
+    // no point in erroring for double-disabling
+    return NS_OK;
+  }
+
+  return CrashReporter::UnsetExceptionHandler();
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetServerURL(nsIURL** aServerURL) {
+  NS_ENSURE_ARG_POINTER(aServerURL);
+  if (!CrashReporter::GetEnabled()) return NS_ERROR_NOT_INITIALIZED;
+
+  nsAutoCString data;
+  if (!CrashReporter::GetServerURL(data)) {
+    return NS_ERROR_FAILURE;
+  }
+  nsCOMPtr<nsIURI> uri;
+  NS_NewURI(getter_AddRefs(uri), data);
+  if (!uri) return NS_ERROR_FAILURE;
+
+  nsCOMPtr<nsIURL> url;
+  url = do_QueryInterface(uri);
+  NS_ADDREF(*aServerURL = url);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::SetServerURL(nsIURL* aServerURL) {
+  // Only allow https or http URLs
+  if (!aServerURL->SchemeIs("http") && !aServerURL->SchemeIs("https")) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  nsAutoCString spec;
+  nsresult rv = aServerURL->GetSpec(spec);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return CrashReporter::SetServerURL(spec);
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetMinidumpPath(nsIFile** aMinidumpPath) {
+  if (!CrashReporter::GetEnabled()) return NS_ERROR_NOT_INITIALIZED;
+
+  nsAutoString path;
+  if (!CrashReporter::GetMinidumpPath(path)) return NS_ERROR_FAILURE;
+
+  nsresult rv = NS_NewLocalFile(path, false, aMinidumpPath);
+  NS_ENSURE_SUCCESS(rv, rv);
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::SetMinidumpPath(nsIFile* aMinidumpPath) {
+  nsAutoString path;
+  nsresult rv = aMinidumpPath->GetPath(path);
+  NS_ENSURE_SUCCESS(rv, rv);
+  return CrashReporter::SetMinidumpPath(path);
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetMinidumpForID(const nsAString& aId, nsIFile** aMinidump) {
+  if (!CrashReporter::GetMinidumpForID(aId, aMinidump)) {
+    return NS_ERROR_FILE_NOT_FOUND;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetExtraFileForID(const nsAString& aId, nsIFile** aExtraFile) {
+  if (!CrashReporter::GetExtraFileForID(aId, aExtraFile)) {
+    return NS_ERROR_FILE_NOT_FOUND;
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::AnnotateCrashReport(const nsACString& key,
+                                  const nsACString& data) {
+  CrashReporter::Annotation annotation;
+
+  if (!AnnotationFromString(annotation, PromiseFlatCString(key).get())) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  return CrashReporter::AnnotateCrashReport(annotation, data);
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::RemoveCrashReportAnnotation(const nsACString& key) {
+  CrashReporter::Annotation annotation;
+
+  if (!AnnotationFromString(annotation, PromiseFlatCString(key).get())) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  return CrashReporter::RemoveCrashReportAnnotation(annotation);
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::IsAnnotationAllowlistedForPing(const nsACString& aValue,
+                                             bool* aIsAllowlisted) {
+  CrashReporter::Annotation annotation;
+
+  if (!AnnotationFromString(annotation, PromiseFlatCString(aValue).get())) {
+    return NS_ERROR_INVALID_ARG;
+  }
+
+  *aIsAllowlisted = CrashReporter::IsAnnotationAllowlistedForPing(annotation);
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::AppendAppNotesToCrashReport(const nsACString& data) {
+  return CrashReporter::AppendAppNotesToCrashReport(data);
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::RegisterAppMemory(uint64_t pointer, uint64_t len) {
+  return CrashReporter::RegisterAppMemory((void*)pointer, len);
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::WriteMinidumpForException(void* aExceptionInfo) {
+#ifdef XP_WIN
+  return CrashReporter::WriteMinidumpForException(
+      static_cast<EXCEPTION_POINTERS*>(aExceptionInfo));
+#else
+  return NS_ERROR_NOT_IMPLEMENTED;
+#endif
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::AppendObjCExceptionInfoToAppNotes(void* aException) {
+#ifdef XP_MACOSX
+  return CrashReporter::AppendObjCExceptionInfoToAppNotes(aException);
+#else
+  return NS_ERROR_NOT_IMPLEMENTED;
+#endif
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::GetSubmitReports(bool* aEnabled) {
+  return CrashReporter::GetSubmitReports(aEnabled);
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::SetSubmitReports(bool aEnabled) {
+  return CrashReporter::SetSubmitReports(aEnabled);
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::UpdateCrashEventsDir() {
+  CrashReporter::UpdateCrashEventsDir();
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsXULAppInfo::SaveMemoryReport() {
+  if (!CrashReporter::GetEnabled()) {
+    return NS_ERROR_NOT_INITIALIZED;
+  }
+  nsCOMPtr<nsIFile> file;
+  nsresult rv = CrashReporter::GetDefaultMemoryReportFile(getter_AddRefs(file));
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+
+  nsString path;
+  file->GetPath(path);
+
+  nsCOMPtr<nsIMemoryInfoDumper> dumper =
+      do_GetService("@mozilla.org/memory-info-dumper;1");
+  if (NS_WARN_IF(!dumper)) {
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  rv = dumper->DumpMemoryReportsToNamedFile(
+      path, this, file, true /* anonymize */, false /* minimizeMemoryUsage */);
+  if (NS_WARN_IF(NS_FAILED(rv))) {
+    return rv;
+  }
+  return NS_OK;
+}
+
+// This method is from nsIFInishDumpingCallback.
+NS_IMETHODIMP
+nsXULAppInfo::Callback(nsISupports* aData) {
+  nsCOMPtr<nsIFile> file = do_QueryInterface(aData);
+  MOZ_ASSERT(file);
+
+  CrashReporter::SetMemoryReportFile(file);
+  return NS_OK;
+}
+
+static const nsXULAppInfo kAppInfo;
+namespace mozilla {
+nsresult AppInfoConstructor(REFNSIID aIID, void** aResult) {
+  return const_cast<nsXULAppInfo*>(&kAppInfo)->QueryInterface(aIID, aResult);
+}
+}  // namespace mozilla
+
+bool gLogConsoleErrors = false;
+
+#define NS_ENSURE_TRUE_LOG(x, ret)               \
+  PR_BEGIN_MACRO                                 \
+  if (MOZ_UNLIKELY(!(x))) {                      \
+    NS_WARNING("NS_ENSURE_TRUE(" #x ") failed"); \
+    gLogConsoleErrors = true;                    \
+    return ret;                                  \
+  }                                              \
+  PR_END_MACRO
+
+#define NS_ENSURE_SUCCESS_LOG(res, ret) \
+  NS_ENSURE_TRUE_LOG(NS_SUCCEEDED(res), ret)
+
+/**
+ * Because we're starting/stopping XPCOM several times in different scenarios,
+ * this class is a stack-based critter that makes sure that XPCOM is shut down
+ * during early returns.
+ */
+
+class ScopedXPCOMStartup {
+ public:
+  ScopedXPCOMStartup() : mServiceManager(nullptr) {}
+  ~ScopedXPCOMStartup();
+
+  nsresult Initialize(bool aInitJSContext = true);
+  nsresult SetWindowCreator(nsINativeAppSupport* native);
+
+ private:
+  nsIServiceManager* mServiceManager;
+  static nsINativeAppSupport* gNativeAppSupport;
+
+  friend already_AddRefed<nsINativeAppSupport> NS_GetNativeAppSupport();
+};
+
+ScopedXPCOMStartup::~ScopedXPCOMStartup() {
+  NS_IF_RELEASE(gNativeAppSupport);
+
+  if (mServiceManager) {
+#ifdef XP_MACOSX
+    // On OS X, we need a pool to catch cocoa objects that are autoreleased
+    // during teardown.
+    mozilla::MacAutoreleasePool pool;
+#endif
+
+    nsCOMPtr<nsIAppStartup> appStartup(components::AppStartup::Service());
+    if (appStartup) appStartup->DestroyHiddenWindow();
+
+    gDirServiceProvider->DoShutdown();
+    PROFILER_MARKER_UNTYPED("Shutdown early", OTHER);
+
+    WriteConsoleLog();
+
+    NS_ShutdownXPCOM(mServiceManager);
+    mServiceManager = nullptr;
+  }
+}
+
+nsresult ScopedXPCOMStartup::Initialize(bool aInitJSContext) {
+  NS_ASSERTION(gDirServiceProvider, "Should not get here!");
+
+  nsresult rv;
+
+  rv = NS_InitXPCOM(&mServiceManager, gDirServiceProvider->GetAppDir(),
+                    gDirServiceProvider, aInitJSContext);
+  if (NS_FAILED(rv)) {
+    NS_ERROR("Couldn't start xpcom!");
+    mServiceManager = nullptr;
+  } else {
+#ifdef DEBUG
+    nsCOMPtr<nsIComponentRegistrar> reg = do_QueryInterface(mServiceManager);
+    NS_ASSERTION(reg, "Service Manager doesn't QI to Registrar.");
+#endif
+  }
+
+  return rv;
+}
+
+/**
+ * This is a little factory class that serves as a singleton-service-factory
+ * for the nativeappsupport object.
+ */
+class nsSingletonFactory final : public nsIFactory {
+ public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSIFACTORY
+
+  explicit nsSingletonFactory(nsISupports* aSingleton);
+
+ private:
+  ~nsSingletonFactory() = default;
+  nsCOMPtr<nsISupports> mSingleton;
+};
+
+nsSingletonFactory::nsSingletonFactory(nsISupports* aSingleton)
+    : mSingleton(aSingleton) {
+  NS_ASSERTION(mSingleton, "Singleton was null!");
+}
+
+NS_IMPL_ISUPPORTS(nsSingletonFactory, nsIFactory)
+
+NS_IMETHODIMP
+nsSingletonFactory::CreateInstance(const nsIID& aIID, void** aResult) {
+  return mSingleton->QueryInterface(aIID, aResult);
+}
+
+/**
+ * Set our windowcreator on the WindowWatcher service.
+ */
+nsresult ScopedXPCOMStartup::SetWindowCreator(nsINativeAppSupport* native) {
+  nsresult rv;
+
+  NS_IF_ADDREF(gNativeAppSupport = native);
+
+  nsCOMPtr<nsIWindowCreator> creator(components::AppStartup::Service());
+  if (!creator) return NS_ERROR_UNEXPECTED;
+
+  nsCOMPtr<nsIWindowWatcher> wwatch(
+      do_GetService(NS_WINDOWWATCHER_CONTRACTID, &rv));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  return wwatch->SetWindowCreator(creator);
+}
+
+/* static */ already_AddRefed<nsINativeAppSupport> NS_GetNativeAppSupport() {
+  if (!ScopedXPCOMStartup::gNativeAppSupport) {
+    return nullptr;
+  }
+
+  return do_AddRef(ScopedXPCOMStartup::gNativeAppSupport);
+}
+
+nsINativeAppSupport* ScopedXPCOMStartup::gNativeAppSupport;
+
+static void DumpArbitraryHelp() {
+  nsresult rv;
+
+  ScopedLogging log;
+
+  {
+    ScopedXPCOMStartup xpcom;
+    xpcom.Initialize();
+
+    nsCOMPtr<nsICommandLineRunner> cmdline(new nsCommandLine());
+
+    nsCString text;
+    rv = cmdline->GetHelpText(text);
+    if (NS_SUCCEEDED(rv)) printf("%s", text.get());
+  }
+}
+
+// English text needs to go into a dtd file.
+// But when this is called we have no components etc. These strings must either
+// be here, or in a native resource file.
+static void DumpHelp() {
+  printf(
+      "Usage: %s [ options ... ] [URL]\n"
+      "       where options include:\n\n",
+      gArgv[0]);
+
+#ifdef MOZ_X11
+  printf(
+      "X11 options\n"
+      "  --display=DISPLAY  X display to use\n"
+      "  --sync             Make X calls synchronous\n");
+#endif
+#ifdef XP_UNIX
+  printf(
+      "  --g-fatal-warnings Make all warnings fatal\n"
+      "\n%s options\n",
+      (const char*)gAppData->name);
+#endif
+
+  printf(
+      "  -h or --help       Print this message.\n"
+      "  -v or --version    Print %s version.\n"
+      "  --full-version     Print %s version, build and platform build ids.\n"
+      "  -P <profile>       Start with <profile>.\n"
+      "  --profile <path>   Start with profile at <path>.\n"
+      "  --migration        Start with migration wizard.\n"
+      "  --ProfileManager   Start with ProfileManager.\n"
+#ifdef MOZ_HAS_REMOTE
+      "  --no-remote        Do not accept or send remote commands; implies\n"
+      "                     --new-instance.\n"
+      "  --new-instance     Open new instance, not a new window in running "
+      "instance.\n"
+#endif
+      "  --safe-mode        Disables extensions and themes for this session.\n"
+#ifdef MOZ_BLOCK_PROFILE_DOWNGRADE
+      "  --allow-downgrade  Allows downgrading a profile.\n"
+#endif
+      "  --MOZ_LOG=<modules> Treated as MOZ_LOG=<modules> environment "
+      "variable,\n"
+      "                     overrides it.\n"
+      "  --MOZ_LOG_FILE=<file> Treated as MOZ_LOG_FILE=<file> environment "
+      "variable,\n"
+      "                     overrides it. If MOZ_LOG_FILE is not specified as "
+      "an\n"
+      "                     argument or as an environment variable, logging "
+      "will be\n"
+      "                     written to stdout.\n",
+      (const char*)gAppData->name, (const char*)gAppData->name);
+
+#if defined(XP_WIN)
+  printf("  --console          Start %s with a debugging console.\n",
+         (const char*)gAppData->name);
+#endif
+
+#if defined(XP_WIN) || defined(MOZ_WIDGET_GTK) || defined(XP_MACOSX)
+  printf("  --headless         Run without a GUI.\n");
+#endif
+
+  // this works, but only after the components have registered.  so if you drop
+  // in a new command line handler, --help won't not until the second run. out
+  // of the bug, because we ship a component.reg file, it works correctly.
+  DumpArbitraryHelp();
+}
+
+static inline void DumpVersion() {
+  if (gAppData->vendor && *gAppData->vendor) {
+    printf("%s ", (const char*)gAppData->vendor);
+  }
+  printf("%s ", (const char*)gAppData->name);
+
+  // Use the displayed version
+  // For example, for beta, we would display 42.0b2 instead of 42.0
+  printf("%s", MOZ_STRINGIFY(MOZ_APP_VERSION_DISPLAY));
+
+  if (gAppData->copyright && *gAppData->copyright) {
+    printf(", %s", (const char*)gAppData->copyright);
+  }
+  printf("\n");
+}
+
+static inline void DumpFullVersion() {
+  if (gAppData->vendor && *gAppData->vendor) {
+    printf("%s ", (const char*)gAppData->vendor);
+  }
+  printf("%s ", (const char*)gAppData->name);
+
+  // Use the displayed version
+  // For example, for beta, we would display 42.0b2 instead of 42.0
+  printf("%s ", MOZ_STRINGIFY(MOZ_APP_VERSION_DISPLAY));
+
+  printf("%s ", (const char*)gAppData->buildID);
+  printf("%s ", (const char*)PlatformBuildID());
+  if (gAppData->copyright && *gAppData->copyright) {
+    printf(", %s", (const char*)gAppData->copyright);
+  }
+  printf("\n");
+}
+
+void XRE_InitOmnijar(nsIFile* greOmni, nsIFile* appOmni) {
+  mozilla::Omnijar::Init(greOmni, appOmni);
+}
+
+nsresult XRE_GetBinaryPath(nsIFile** aResult) {
+  return mozilla::BinaryPath::GetFile(aResult);
+}
+
+#ifdef XP_WIN
+#  include "nsWindowsRestart.cpp"
+#  include <shellapi.h>
+
+typedef BOOL(WINAPI* SetProcessDEPPolicyFunc)(DWORD dwFlags);
+
+static void RegisterApplicationRestartChanged(const char* aPref, void* aData) {
+  DWORD cchCmdLine = 0;
+  HRESULT rc = ::GetApplicationRestartSettings(::GetCurrentProcess(), nullptr,
+                                               &cchCmdLine, nullptr);
+  bool wasRegistered = false;
+  if (rc == S_OK) {
+    wasRegistered = true;
+  }
+
+  if (Preferences::GetBool(PREF_WIN_REGISTER_APPLICATION_RESTART, false) &&
+      !wasRegistered) {
+    // Make the command line to use when restarting.
+    // Excludes argv[0] because RegisterApplicationRestart adds the
+    // executable name, replace that temporarily with -os-restarted
+    char* exeName = gRestartArgv[0];
+    gRestartArgv[0] = const_cast<char*>("-os-restarted");
+    wchar_t** restartArgvConverted =
+        AllocConvertUTF8toUTF16Strings(gRestartArgc, gRestartArgv);
+    gRestartArgv[0] = exeName;
+
+    mozilla::UniquePtr<wchar_t[]> restartCommandLine;
+    if (restartArgvConverted) {
+      restartCommandLine =
+          mozilla::MakeCommandLine(gRestartArgc, restartArgvConverted);
+      FreeAllocStrings(gRestartArgc, restartArgvConverted);
+    }
+
+    if (restartCommandLine) {
+      // Flags RESTART_NO_PATCH and RESTART_NO_REBOOT are not set, so we
+      // should be restarted if terminated by an update or restart.
+      ::RegisterApplicationRestart(restartCommandLine.get(),
+                                   RESTART_NO_CRASH | RESTART_NO_HANG);
+    }
+  } else if (wasRegistered) {
+    ::UnregisterApplicationRestart();
+  }
+}
+
+static void OnAlteredPrefetchPrefChanged(const char* aPref, void* aData) {
+  int32_t prefVal = Preferences::GetInt(PREF_WIN_ALTERED_DLL_PREFETCH, 0);
+
+  mozilla::DllPrefetchExperimentRegistryInfo prefetchRegInfo;
+  mozilla::DebugOnly<mozilla::Result<Ok, nsresult>> reflectResult =
+      prefetchRegInfo.ReflectPrefToRegistry(prefVal);
+
+  MOZ_ASSERT(reflectResult.value.isOk());
+}
+
+static void SetupAlteredPrefetchPref() {
+  mozilla::DllPrefetchExperimentRegistryInfo prefetchRegInfo;
+
+  mozilla::DebugOnly<mozilla::Result<Ok, nsresult>> reflectResult =
+      prefetchRegInfo.ReflectPrefToRegistry(
+          Preferences::GetInt(PREF_WIN_ALTERED_DLL_PREFETCH, 0));
+  MOZ_ASSERT(reflectResult.value.isOk());
+
+  Preferences::RegisterCallback(&OnAlteredPrefetchPrefChanged,
+                                PREF_WIN_ALTERED_DLL_PREFETCH);
+}
+
+static void ReflectSkeletonUIPrefToRegistry(const char* aPref, void* aData) {
+  Unused << aPref;
+  Unused << aData;
+
+  bool shouldBeEnabled =
+      Preferences::GetBool(kPrefPreXulSkeletonUI, false) &&
+      Preferences::GetBool(kPrefBrowserStartupBlankWindow, false) &&
+      LookAndFeel::DrawInTitlebar();
+  if (shouldBeEnabled && Preferences::HasUserValue(kPrefThemeId)) {
+    nsCString themeId;
+    Preferences::GetCString(kPrefThemeId, themeId);
+    if (themeId.EqualsLiteral("default-theme@mozilla.org")) {
+      Unused << SetPreXULSkeletonUIThemeId(ThemeMode::Default);
+    } else if (themeId.EqualsLiteral("firefox-compact-dark@mozilla.org")) {
+      Unused << SetPreXULSkeletonUIThemeId(ThemeMode::Dark);
+    } else if (themeId.EqualsLiteral("firefox-compact-light@mozilla.org")) {
+      Unused << SetPreXULSkeletonUIThemeId(ThemeMode::Light);
+    } else {
+      shouldBeEnabled = false;
+    }
+  } else if (shouldBeEnabled) {
+    Unused << SetPreXULSkeletonUIThemeId(ThemeMode::Default);
+  }
+
+  if (GetPreXULSkeletonUIEnabled() != shouldBeEnabled) {
+    Unused << SetPreXULSkeletonUIEnabledIfAllowed(shouldBeEnabled);
+  }
+}
+
+static void SetupSkeletonUIPrefs() {
+  ReflectSkeletonUIPrefToRegistry(nullptr, nullptr);
+  Preferences::RegisterCallback(&ReflectSkeletonUIPrefToRegistry,
+                                kPrefPreXulSkeletonUI);
+  Preferences::RegisterCallback(&ReflectSkeletonUIPrefToRegistry,
+                                kPrefBrowserStartupBlankWindow);
+  Preferences::RegisterCallback(&ReflectSkeletonUIPrefToRegistry, kPrefThemeId);
+  Preferences::RegisterCallback(
+      &ReflectSkeletonUIPrefToRegistry,
+      nsDependentCString(StaticPrefs::GetPrefName_browser_tabs_inTitlebar()));
+}
+
+#  if defined(MOZ_LAUNCHER_PROCESS)
+
+static void OnLauncherPrefChanged(const char* aPref, void* aData) {
+  bool prefVal = Preferences::GetBool(PREF_WIN_LAUNCHER_PROCESS_ENABLED, true);
+
+  mozilla::LauncherRegistryInfo launcherRegInfo;
+  mozilla::DebugOnly<mozilla::LauncherVoidResult> reflectResult =
+      launcherRegInfo.ReflectPrefToRegistry(prefVal);
+  MOZ_ASSERT(reflectResult.inspect().isOk());
+}
+
+static void OnLauncherTelemetryPrefChanged(const char* aPref, void* aData) {
+  bool prefVal = Preferences::GetBool(kPrefHealthReportUploadEnabled, true);
+
+  mozilla::LauncherRegistryInfo launcherRegInfo;
+  mozilla::DebugOnly<mozilla::LauncherVoidResult> reflectResult =
+      launcherRegInfo.ReflectTelemetryPrefToRegistry(prefVal);
+  MOZ_ASSERT(reflectResult.inspect().isOk());
+}
+
+static void SetupLauncherProcessPref() {
+  if (gLauncherProcessState) {
+    // We've already successfully run
+    return;
+  }
+
+  mozilla::LauncherRegistryInfo launcherRegInfo;
+
+  mozilla::LauncherResult<mozilla::LauncherRegistryInfo::EnabledState>
+      enabledState = launcherRegInfo.IsEnabled();
+
+  if (enabledState.isOk()) {
+    gLauncherProcessState = Some(enabledState.unwrap());
+
+    CrashReporter::AnnotateCrashReport(
+        CrashReporter::Annotation::LauncherProcessState,
+        static_cast<uint32_t>(enabledState.unwrap()));
+
+    // Reflect the launcher process registry state into user prefs
+    Preferences::SetBool(
+        PREF_WIN_LAUNCHER_PROCESS_ENABLED,
+        enabledState.unwrap() !=
+            mozilla::LauncherRegistryInfo::EnabledState::ForceDisabled);
+  }
+
+  mozilla::DebugOnly<mozilla::LauncherVoidResult> reflectResult =
+      launcherRegInfo.ReflectTelemetryPrefToRegistry(
+          Preferences::GetBool(kPrefHealthReportUploadEnabled, true));
+  MOZ_ASSERT(reflectResult.inspect().isOk());
+
+  Preferences::RegisterCallback(&OnLauncherPrefChanged,
+                                PREF_WIN_LAUNCHER_PROCESS_ENABLED);
+  Preferences::RegisterCallback(&OnLauncherTelemetryPrefChanged,
+                                kPrefHealthReportUploadEnabled);
+}
+
+#  endif  // defined(MOZ_LAUNCHER_PROCESS)
+
+#  if defined(MOZ_DEFAULT_BROWSER_AGENT)
+
+#    define DEFAULT_BROWSER_AGENT_KEY_NAME \
+      "SOFTWARE\\" MOZ_APP_VENDOR "\\" MOZ_APP_NAME "\\Default Browser Agent"
+
+static nsresult PrependRegistryValueName(nsAutoString& aValueName) {
+  nsresult rv;
+
+  nsCOMPtr<nsIFile> binaryPath;
+  rv = XRE_GetBinaryPath(getter_AddRefs(binaryPath));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsCOMPtr<nsIFile> binaryDir;
+  rv = binaryPath->GetParent(getter_AddRefs(binaryDir));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsAutoString prefix;
+  rv = binaryDir->GetPath(prefix);
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  prefix.AppendLiteral("|");
+  aValueName.Insert(prefix, 0);
+
+  return NS_OK;
+}
+
+static void OnDefaultAgentTelemetryPrefChanged(const char* aPref, void* aData) {
+  nsresult rv;
+  nsAutoString valueName;
+  if (strcmp(aPref, kPrefHealthReportUploadEnabled) == 0) {
+    valueName.AssignLiteral("DisableTelemetry");
+  } else if (strcmp(aPref, kPrefDefaultAgentEnabled) == 0) {
+    valueName.AssignLiteral("DisableDefaultBrowserAgent");
+  } else {
+    return;
+  }
+  rv = PrependRegistryValueName(valueName);
+  NS_ENSURE_SUCCESS_VOID(rv);
+
+  nsCOMPtr<nsIWindowsRegKey> regKey =
+      do_CreateInstance("@mozilla.org/windows-registry-key;1", &rv);
+  NS_ENSURE_SUCCESS_VOID(rv);
+
+  nsAutoString keyName;
+  keyName.AppendLiteral(DEFAULT_BROWSER_AGENT_KEY_NAME);
+  rv = regKey->Create(nsIWindowsRegKey::ROOT_KEY_CURRENT_USER, keyName,
+                      nsIWindowsRegKey::ACCESS_WRITE);
+
+  bool prefVal = Preferences::GetBool(aPref, true);
+
+  // We're recording whether the pref is *disabled*, so invert the value.
+  rv = regKey->WriteIntValue(valueName, prefVal ? 0 : 1);
+  NS_ENSURE_SUCCESS_VOID(rv);
+}
+
+static void OnSetDefaultBrowserUserChoicePrefChanged(const char* aPref,
+                                                     void* aData) {
+  nsresult rv;
+  if (strcmp(aPref, kPrefSetDefaultBrowserUserChoicePref) != 0) {
+    return;
+  }
+  nsAutoString valueName;
+  valueName.AssignLiteral("SetDefaultBrowserUserChoice");
+  rv = PrependRegistryValueName(valueName);
+  NS_ENSURE_SUCCESS_VOID(rv);
+
+  nsCOMPtr<nsIWindowsRegKey> regKey =
+      do_CreateInstance("@mozilla.org/windows-registry-key;1", &rv);
+  NS_ENSURE_SUCCESS_VOID(rv);
+
+  nsAutoString keyName;
+  keyName.AppendLiteral(DEFAULT_BROWSER_AGENT_KEY_NAME);
+  rv = regKey->Create(nsIWindowsRegKey::ROOT_KEY_CURRENT_USER, keyName,
+                      nsIWindowsRegKey::ACCESS_WRITE);
+
+  bool prefVal = Preferences::GetBool(aPref, true);
+
+  rv = regKey->WriteIntValue(valueName, prefVal);
+  NS_ENSURE_SUCCESS_VOID(rv);
+}
+
+static void OnDefaultAgentRemoteSettingsPrefChanged(const char* aPref,
+                                                    void* aData) {
+  nsresult rv;
+  nsAutoString valueName;
+  if (strcmp(aPref, kPrefServicesSettingsServer) == 0) {
+    valueName.AssignLiteral("ServicesSettingsServer");
+  } else if (strcmp(aPref, kPrefSecurityContentSignatureRootHash) == 0) {
+    valueName.AssignLiteral("SecurityContentSignatureRootHash");
+  } else {
+    return;
+  }
+  rv = PrependRegistryValueName(valueName);
+  NS_ENSURE_SUCCESS_VOID(rv);
+
+  nsCOMPtr<nsIWindowsRegKey> regKey =
+      do_CreateInstance("@mozilla.org/windows-registry-key;1", &rv);
+  NS_ENSURE_SUCCESS_VOID(rv);
+
+  nsAutoString keyName;
+  keyName.AppendLiteral(DEFAULT_BROWSER_AGENT_KEY_NAME);
+  rv = regKey->Create(nsIWindowsRegKey::ROOT_KEY_CURRENT_USER, keyName,
+                      nsIWindowsRegKey::ACCESS_WRITE);
+
+  NS_ENSURE_SUCCESS_VOID(rv);
+
+  nsAutoString prefVal;
+  rv = Preferences::GetString(aPref, prefVal);
+  NS_ENSURE_SUCCESS_VOID(rv);
+
+  if (prefVal.IsEmpty()) {
+    rv = regKey->RemoveValue(valueName);
+  } else {
+    rv = regKey->WriteStringValue(valueName, prefVal);
+  }
+  NS_ENSURE_SUCCESS_VOID(rv);
+}
+
+static void SetDefaultAgentLastRunTime() {
+  nsresult rv;
+  nsAutoString valueName;
+  valueName.AppendLiteral("AppLastRunTime");
+  rv = PrependRegistryValueName(valueName);
+  NS_ENSURE_SUCCESS_VOID(rv);
+
+  nsCOMPtr<nsIWindowsRegKey> regKey =
+      do_CreateInstance("@mozilla.org/windows-registry-key;1", &rv);
+  NS_ENSURE_SUCCESS_VOID(rv);
+
+  nsAutoString keyName;
+  keyName.AppendLiteral(DEFAULT_BROWSER_AGENT_KEY_NAME);
+  rv = regKey->Create(nsIWindowsRegKey::ROOT_KEY_CURRENT_USER, keyName,
+                      nsIWindowsRegKey::ACCESS_WRITE);
+  NS_ENSURE_SUCCESS_VOID(rv);
+
+  FILETIME fileTime;
+  GetSystemTimeAsFileTime(&fileTime);
+
+  ULARGE_INTEGER integerTime;
+  integerTime.u.LowPart = fileTime.dwLowDateTime;
+  integerTime.u.HighPart = fileTime.dwHighDateTime;
+
+  rv = regKey->WriteInt64Value(valueName, integerTime.QuadPart);
+  NS_ENSURE_SUCCESS_VOID(rv);
+}
+
+#  endif  // defined(MOZ_DEFAULT_BROWSER_AGENT)
+
+#endif  // XP_WIN
+
+void UnlockProfile() {
+  if (gProfileLock) {
+    gProfileLock->Unlock();
+  }
+}
+
+nsresult LaunchChild(bool aBlankCommandLine, bool aTryExec) {
+  // Restart this process by exec'ing it into the current process
+  // if supported by the platform.  Otherwise, use NSPR.
+
+#ifdef MOZ_JPROF
+  // make sure JPROF doesn't think we're E10s
+  unsetenv("JPROF_ISCHILD");
+#endif
+
+  if (aBlankCommandLine) {
+    gRestartArgc = 1;
+    gRestartArgv[gRestartArgc] = nullptr;
+  }
+
+#if defined(MOZ_HAS_REMOTE)
+  if (gRestartWithoutRemote) {
+    SaveToEnv("MOZ_NO_REMOTE=1");
+  }
+#endif
+
+  SaveToEnv("MOZ_LAUNCHED_CHILD=1");
+#if defined(MOZ_LAUNCHER_PROCESS)
+  SaveToEnv("MOZ_LAUNCHER_PROCESS=1");
+#endif  // defined(MOZ_LAUNCHER_PROCESS)
+
+#if !defined(MOZ_WIDGET_ANDROID)  // Android has separate restart code.
+#  if defined(XP_MACOSX)
+  CommandLineServiceMac::SetupMacCommandLine(gRestartArgc, gRestartArgv, true);
+  LaunchChildMac(gRestartArgc, gRestartArgv);
+#  else
+  nsCOMPtr<nsIFile> lf;
+  nsresult rv = XRE_GetBinaryPath(getter_AddRefs(lf));
+  if (NS_FAILED(rv)) return rv;
+
+#    if defined(XP_WIN)
+  nsAutoString exePath;
+  rv = lf->GetPath(exePath);
+  if (NS_FAILED(rv)) return rv;
+
+  HANDLE hProcess;
+  if (!WinLaunchChild(exePath.get(), gRestartArgc, gRestartArgv, nullptr,
+                      &hProcess))
+    return NS_ERROR_FAILURE;
+  // Keep the current process around until the restarted process has created
+  // its message queue, to avoid the launched process's windows being forced
+  // into the background.
+  mozilla::WaitForInputIdle(hProcess);
+  ::CloseHandle(hProcess);
+
+#    else
+  nsAutoCString exePath;
+  rv = lf->GetNativePath(exePath);
+  if (NS_FAILED(rv)) return rv;
+
+#      if defined(XP_UNIX)
+  if (aTryExec) {
+    execv(exePath.get(), gRestartArgv);
+
+    // If execv returns we know it's because it failed.
+    return NS_ERROR_FAILURE;
+  }
+#      endif
+  if (PR_CreateProcessDetached(exePath.get(), gRestartArgv, nullptr, nullptr) ==
+      PR_FAILURE) {
+    return NS_ERROR_FAILURE;
+  }
+
+  // Note that we don't know if the child process starts okay, if it
+  // immediately returns non-zero then we may mask that by returning a zero
+  // exit status.
+
+#    endif  // WP_WIN
+#  endif    // WP_MACOSX
+#endif      // MOZ_WIDGET_ANDROID
+
+  return NS_ERROR_LAUNCHED_CHILD_PROCESS;
+}
+
+static const char kProfileProperties[] =
+    "chrome://mozapps/locale/profile/profileSelection.properties";
+
+namespace {
+
+/**
+ * This class, instead of a raw nsresult, should be the return type of any
+ * function called by SelectProfile that initializes XPCOM.
+ */
+class ReturnAbortOnError {
+ public:
+  MOZ_IMPLICIT ReturnAbortOnError(nsresult aRv) { mRv = ConvertRv(aRv); }
+
+  operator nsresult() { return mRv; }
+
+ private:
+  inline nsresult ConvertRv(nsresult aRv) {
+    if (NS_SUCCEEDED(aRv) || aRv == NS_ERROR_LAUNCHED_CHILD_PROCESS) {
+      return aRv;
+    }
+#ifdef MOZ_BACKGROUNDTASKS
+    // A background task that fails to lock its profile will return
+    // NS_ERROR_UNEXPECTED and this will allow the task to exit with a
+    // non-zero exit code.
+    if (aRv == NS_ERROR_UNEXPECTED && BackgroundTasks::IsBackgroundTaskMode()) {
+      return aRv;
+    }
+#endif
+    return NS_ERROR_ABORT;
+  }
+
+  nsresult mRv;
+};
+
+}  // namespace
+
+static nsresult ProfileMissingDialog(nsINativeAppSupport* aNative) {
+#ifdef MOZ_WIDGET_ANDROID
+  // We cannot really do anything this early during initialization, so we just
+  // return as this is likely the effect of misconfiguration on the test side.
+  // Non-test code paths cannot set the profile folder, which is always the
+  // default one.
+  Output(true, "Could not find profile folder.\n");
+  return NS_ERROR_ABORT;
+#else
+#  ifdef MOZ_BACKGROUNDTASKS
+  if (BackgroundTasks::IsBackgroundTaskMode()) {
+    // We should never get to this point in background task mode.
+    Output(false,
+           "Could not determine any profile running in backgroundtask mode!\n");
+    return NS_ERROR_ABORT;
+  }
+#  endif  // MOZ_BACKGROUNDTASKS
+
+  nsresult rv;
+
+  ScopedXPCOMStartup xpcom;
+  rv = xpcom.Initialize();
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  rv = xpcom.SetWindowCreator(aNative);
+  NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);
+
+  {  // extra scoping is needed so we release these components before xpcom
+     // shutdown
+    nsCOMPtr<nsIStringBundleService> sbs =
+        mozilla::components::StringBundle::Service();
+    NS_ENSURE_TRUE(sbs, NS_ERROR_FAILURE);
+
+    nsCOMPtr<nsIStringBundle> sb;
+    sbs->CreateBundle(kProfileProperties, getter_AddRefs(sb));
+    NS_ENSURE_TRUE_LOG(sbs, NS_ERROR_FAILURE);
+
+    NS_ConvertUTF8toUTF16 appName(gAppData->name);
+    AutoTArray<nsString, 2> params = {appName, appName};
+
+    // profileMissing
+    nsAutoString missingMessage;
+    rv = sb->FormatStringFromName("profileMissing", params, missingMessage);
+    NS_ENSURE_SUCCESS(rv, NS_ERROR_ABORT);
+
+    nsAutoString missingTitle;
+    params.SetLength(1);
+    rv = sb->FormatStringFromName("profileMissingTitle", params, missingTitle);
+    NS_ENSURE_SUCCESS(rv, NS_ERROR_ABORT);
+
+    nsCOMPtr<nsIPromptService> ps(do_GetService(NS_PROMPTSERVICE_CONTRACTID));
+    NS_ENSURE_TRUE(ps, NS_ERROR_FAILURE);
+
+    ps->Alert(nullptr, missingTitle.get(), missingMessage.get());
+
+    return NS_ERROR_ABORT;
+  }
+#endif    // MOZ_WIDGET_ANDROID
+}
+
+static ReturnAbortOnError ProfileLockedDialog(nsIFile* aProfileDir,
+                                              nsIFile* aProfileLocalDir,
+                                              nsIProfileUnlocker* aUnlocker,
+                                              nsINativeAppSupport* aNative,
+                                              nsIProfileLock** aResult) {
+  nsresult rv;
+
+  bool exists;
+  aProfileDir->Exists(&exists);
+  if (!exists) {
+    return ProfileMissingDialog(aNative);
+  }
+
+  ScopedXPCOMStartup xpcom;
+  rv = xpcom.Initialize();
+  NS_ENSURE_SUCCESS(rv, rv);
+
+#if defined(MOZ_TELEMETRY_REPORTING)
+  // We cannot check if telemetry has been disabled by the user, yet.
+  // So, rely on the build time settings, instead.
+  mozilla::Telemetry::WriteFailedProfileLock(aProfileDir);
+#endif
+
+  rv = xpcom.SetWindowCreator(aNative);
+  NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);
+
+  {  // extra scoping is needed so we release these components before xpcom
+     // shutdown
+    nsCOMPtr<nsIStringBundleService> sbs =
+        mozilla::components::StringBundle::Service();
+    NS_ENSURE_TRUE(sbs, NS_ERROR_FAILURE);
+
+    nsCOMPtr<nsIStringBundle> sb;
+    sbs->CreateBundle(kProfileProperties, getter_AddRefs(sb));
+    NS_ENSURE_TRUE_LOG(sbs, NS_ERROR_FAILURE);
+
+    NS_ConvertUTF8toUTF16 appName(gAppData->name);
+    AutoTArray<nsString, 3> params = {appName, appName, appName};
+
+    nsAutoString killMessage;
+#ifndef XP_MACOSX
+    rv = sb->FormatStringFromName(
+        aUnlocker ? "restartMessageUnlocker" : "restartMessageNoUnlocker2",
+        params, killMessage);
+#else
+    rv = sb->FormatStringFromName(
+        aUnlocker ? "restartMessageUnlockerMac" : "restartMessageNoUnlockerMac",
+        params, killMessage);
+#endif
+    NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);
+
+    params.SetLength(1);
+    nsAutoString killTitle;
+    rv = sb->FormatStringFromName("restartTitle", params, killTitle);
+    NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);
+
+#ifdef MOZ_BACKGROUNDTASKS
+    if (BackgroundTasks::IsBackgroundTaskMode()) {
+      // This error is handled specially to exit with a non-zero exit code.
+      printf_stderr("%s\n", NS_LossyConvertUTF16toASCII(killMessage).get());
+      return NS_ERROR_UNEXPECTED;
+    }
+#endif
+
+    if (gfxPlatform::IsHeadless()) {
+      // TODO: make a way to turn off all dialogs when headless.
+      Output(true, "%s\n", NS_LossyConvertUTF16toASCII(killMessage).get());
+      return NS_ERROR_FAILURE;
+    }
+
+    nsCOMPtr<nsIPromptService> ps(do_GetService(NS_PROMPTSERVICE_CONTRACTID));
+    NS_ENSURE_TRUE(ps, NS_ERROR_FAILURE);
+
+    if (aUnlocker) {
+      int32_t button;
+#ifdef MOZ_WIDGET_ANDROID
+      // On Android we always kill the process if the lock is still being held
+      button = 0;
+#else
+      const uint32_t flags = (nsIPromptService::BUTTON_TITLE_IS_STRING *
+                              nsIPromptService::BUTTON_POS_0) +
+                             (nsIPromptService::BUTTON_TITLE_CANCEL *
+                              nsIPromptService::BUTTON_POS_1);
+
+      bool checkState = false;
+      rv = ps->ConfirmEx(nullptr, killTitle.get(), killMessage.get(), flags,
+                         killTitle.get(), nullptr, nullptr, nullptr,
+                         &checkState, &button);
+      NS_ENSURE_SUCCESS_LOG(rv, rv);
+#endif
+
+      if (button == 0) {
+        rv = aUnlocker->Unlock(nsIProfileUnlocker::FORCE_QUIT);
+        if (NS_FAILED(rv)) {
+          return rv;
+        }
+
+        SaveFileToEnv("XRE_PROFILE_PATH", aProfileDir);
+        SaveFileToEnv("XRE_PROFILE_LOCAL_PATH", aProfileLocalDir);
+
+#if defined(MOZ_HAS_REMOTE)
+        if (gRemoteService) {
+          gRemoteService->UnlockStartup();
+          gRemoteService = nullptr;
+        }
+#endif
+        return LaunchChild(false, true);
+      }
+    } else {
+      rv = ps->Alert(nullptr, killTitle.get(), killMessage.get());
+      NS_ENSURE_SUCCESS_LOG(rv, rv);
+    }
+
+    return NS_ERROR_ABORT;
+  }
+}
+
+static const char kProfileManagerURL[] =
+    "chrome://mozapps/content/profile/profileSelection.xhtml";
+
+static ReturnAbortOnError ShowProfileManager(
+    nsIToolkitProfileService* aProfileSvc, nsINativeAppSupport* aNative) {
+  nsresult rv;
+
+  nsCOMPtr<nsIFile> profD, profLD;
+  bool offline = false;
+  int32_t dialogReturn;
+
+  {
+    ScopedXPCOMStartup xpcom;
+    rv = xpcom.Initialize();
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = xpcom.SetWindowCreator(aNative);
+    NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);
+
+#ifdef XP_MACOSX
+    CommandLineServiceMac::SetupMacCommandLine(gRestartArgc, gRestartArgv,
+                                               true);
+#endif
+
+    {  // extra scoping is needed so we release these components before xpcom
+       // shutdown
+      nsCOMPtr<nsIWindowWatcher> windowWatcher(
+          do_GetService(NS_WINDOWWATCHER_CONTRACTID));
+      nsCOMPtr<nsIDialogParamBlock> ioParamBlock(
+          do_CreateInstance(NS_DIALOGPARAMBLOCK_CONTRACTID));
+      nsCOMPtr<nsIMutableArray> dlgArray(
+          do_CreateInstance(NS_ARRAY_CONTRACTID));
+      NS_ENSURE_TRUE(windowWatcher && ioParamBlock && dlgArray,
+                     NS_ERROR_FAILURE);
+
+      ioParamBlock->SetObjects(dlgArray);
+
+      nsCOMPtr<nsIAppStartup> appStartup(components::AppStartup::Service());
+      NS_ENSURE_TRUE(appStartup, NS_ERROR_FAILURE);
+
+      nsAutoCString features("centerscreen,chrome,modal,titlebar");
+      // If we're launching a private browsing window make sure to set that
+      // feature for the Profile Manager window as well, so it groups correctly
+      // on the Windows taskbar.
+      if (CheckArgExists("private-window") == ARG_FOUND) {
+        features.AppendLiteral(",private");
+      }
+      nsCOMPtr<mozIDOMWindowProxy> newWindow;
+      rv = windowWatcher->OpenWindow(
+          nullptr, nsDependentCString(kProfileManagerURL), "_blank"_ns,
+          features, ioParamBlock, getter_AddRefs(newWindow));
+
+      NS_ENSURE_SUCCESS_LOG(rv, rv);
+
+      rv = ioParamBlock->GetInt(0, &dialogReturn);
+      if (NS_FAILED(rv) || dialogReturn == nsIToolkitProfileService::exit) {
+        return NS_ERROR_ABORT;
+      }
+
+      int32_t startOffline;
+      rv = ioParamBlock->GetInt(1, &startOffline);
+      offline = NS_SUCCEEDED(rv) && startOffline == 1;
+
+      rv = dlgArray->QueryElementAt(0, NS_GET_IID(nsIFile),
+                                    getter_AddRefs(profD));
+      NS_ENSURE_SUCCESS_LOG(rv, rv);
+
+      rv = dlgArray->QueryElementAt(1, NS_GET_IID(nsIFile),
+                                    getter_AddRefs(profLD));
+      NS_ENSURE_SUCCESS_LOG(rv, rv);
+    }
+  }
+
+  if (offline) {
+    SaveToEnv("XRE_START_OFFLINE=1");
+  }
+
+  // User requested that we restart back into the profile manager.
+  if (dialogReturn == nsIToolkitProfileService::restart) {
+    SaveToEnv("XRE_RESTART_TO_PROFILE_MANAGER=1");
+    SaveToEnv("XRE_RESTARTED_BY_PROFILE_MANAGER=1");
+  } else {
+    MOZ_ASSERT(dialogReturn == nsIToolkitProfileService::launchWithProfile);
+    SaveFileToEnv("XRE_PROFILE_PATH", profD);
+    SaveFileToEnv("XRE_PROFILE_LOCAL_PATH", profLD);
+    SaveToEnv("XRE_RESTARTED_BY_PROFILE_MANAGER=1");
+  }
+
+  if (gRestartedByOS) {
+    // Re-add this argument when actually starting the application.
+    char** newArgv =
+        (char**)realloc(gRestartArgv, sizeof(char*) * (gRestartArgc + 2));
+    NS_ENSURE_TRUE(newArgv, NS_ERROR_OUT_OF_MEMORY);
+    gRestartArgv = newArgv;
+    gRestartArgv[gRestartArgc++] = const_cast<char*>("-os-restarted");
+    gRestartArgv[gRestartArgc] = nullptr;
+  }
+#if defined(MOZ_HAS_REMOTE)
+  if (gRemoteService) {
+    gRemoteService->UnlockStartup();
+    gRemoteService = nullptr;
+  }
+#endif
+  return LaunchChild(false, true);
+}
+
+static bool gDoMigration = false;
+static bool gDoProfileReset = false;
+static nsCOMPtr<nsIToolkitProfile> gResetOldProfile;
+
+static nsresult LockProfile(nsINativeAppSupport* aNative, nsIFile* aRootDir,
+                            nsIFile* aLocalDir, nsIToolkitProfile* aProfile,
+                            nsIProfileLock** aResult) {
+  // If you close Firefox and very quickly reopen it, the old Firefox may
+  // still be closing down. Rather than immediately showing the
+  // "Firefox is running but is not responding" message, we spend a few
+  // seconds retrying first.
+
+  static const int kLockRetrySeconds = 5;
+  static const int kLockRetrySleepMS = 100;
+
+  nsresult rv;
+  nsCOMPtr<nsIProfileUnlocker> unlocker;
+  const TimeStamp start = TimeStamp::Now();
+  do {
+    if (aProfile) {
+      rv = aProfile->Lock(getter_AddRefs(unlocker), aResult);
+    } else {
+      rv = NS_LockProfilePath(aRootDir, aLocalDir, getter_AddRefs(unlocker),
+                              aResult);
+    }
+    if (NS_SUCCEEDED(rv)) {
+      StartupTimeline::Record(StartupTimeline::AFTER_PROFILE_LOCKED);
+      return NS_OK;
+    }
+    PR_Sleep(kLockRetrySleepMS);
+  } while (TimeStamp::Now() - start <
+           TimeDuration::FromSeconds(kLockRetrySeconds));
+
+  return ProfileLockedDialog(aRootDir, aLocalDir, unlocker, aNative, aResult);
+}
+
+// Pick a profile. We need to end up with a profile root dir, local dir and
+// potentially an nsIToolkitProfile instance.
+//
+// 1) check for --profile <path>
+// 2) check for -P <name>
+// 3) check for --ProfileManager
+// 4) use the default profile, if there is one
+// 5) if there are *no* profiles, set up profile-migration
+// 6) display the profile-manager UI
+static nsresult SelectProfile(nsToolkitProfileService* aProfileSvc,
+                              nsINativeAppSupport* aNative, nsIFile** aRootDir,
+                              nsIFile** aLocalDir, nsIToolkitProfile** aProfile,
+                              bool* aWasDefaultSelection) {
+  StartupTimeline::Record(StartupTimeline::SELECT_PROFILE);
+
+  nsresult rv;
+
+  if (EnvHasValue("MOZ_RESET_PROFILE_RESTART")) {
+    gDoProfileReset = true;
+    gDoMigration = true;
+  }
+
+  // reset-profile and migration args need to be checked before any profiles are
+  // chosen below.
+  ArgResult ar = CheckArg("reset-profile");
+  if (ar == ARG_FOUND) {
+    gDoProfileReset = true;
+  }
+
+  ar = CheckArg("migration");
+  if (ar == ARG_FOUND) {
+    gDoMigration = true;
+  }
+
+#if defined(XP_WIN)
+  // This arg is only used to indicate to telemetry that a profile refresh
+  // (reset+migration) was requested from the uninstaller, pass this along
+  // via an environment variable for simplicity.
+  ar = CheckArg("uninstaller-profile-refresh");
+  if (ar == ARG_FOUND) {
+    SaveToEnv("MOZ_UNINSTALLER_PROFILE_REFRESH=1");
+  }
+#endif
+
+  if (EnvHasValue("XRE_RESTART_TO_PROFILE_MANAGER")) {
+    return ShowProfileManager(aProfileSvc, aNative);
+  }
+
+  // Ask the profile manager to select the profile directories to use.
+  bool didCreate = false;
+  rv = aProfileSvc->SelectStartupProfile(&gArgc, gArgv, gDoProfileReset,
+                                         aRootDir, aLocalDir, aProfile,
+                                         &didCreate, aWasDefaultSelection);
+
+  if (rv == NS_ERROR_SHOW_PROFILE_MANAGER) {
+    return ShowProfileManager(aProfileSvc, aNative);
+  }
+
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  if (didCreate) {
+    // For a fresh install, we would like to let users decide
+    // to do profile migration on their own later after using.
+    gDoProfileReset = false;
+    gDoMigration = false;
+  }
+
+  if (gDoProfileReset && !*aProfile) {
+    NS_WARNING("Profile reset is only supported for named profiles.");
+    return NS_ERROR_ABORT;
+  }
+
+  // No profile could be found. This generally shouldn't happen, a new profile
+  // should be created in all cases except for profile reset which is covered
+  // above, but just in case...
+  if (!*aRootDir) {
+    NS_WARNING("Failed to select or create profile.");
+    return NS_ERROR_ABORT;
+  }
+
+  return NS_OK;
+}
+
+#ifdef MOZ_BLOCK_PROFILE_DOWNGRADE
+struct FileWriteFunc final : public JSONWriteFunc {
+  FILE* mFile;
+  explicit FileWriteFunc(FILE* aFile) : mFile(aFile) {}
+
+  void Write(const Span<const char>& aStr) final {
+    fprintf(mFile, "%.*s", int(aStr.size()), aStr.data());
+  }
+};
+
+static void SubmitDowngradeTelemetry(const nsCString& aLastVersion,
+                                     bool aHasSync, int32_t aButton) {
+  nsCOMPtr<nsIPrefService> prefSvc =
+      do_GetService("@mozilla.org/preferences-service;1");
+  NS_ENSURE_TRUE_VOID(prefSvc);
+
+  nsCOMPtr<nsIPrefBranch> prefBranch = do_QueryInterface(prefSvc);
+  NS_ENSURE_TRUE_VOID(prefBranch);
+
+  bool enabled;
+  nsresult rv =
+      prefBranch->GetBoolPref(kPrefHealthReportUploadEnabled, &enabled);
+  NS_ENSURE_SUCCESS_VOID(rv);
+  if (!enabled) {
+    return;
+  }
+
+  nsCString server;
+  rv = prefBranch->GetCharPref("toolkit.telemetry.server", server);
+  NS_ENSURE_SUCCESS_VOID(rv);
+
+  nsCString clientId;
+  rv = prefBranch->GetCharPref("toolkit.telemetry.cachedClientID", clientId);
+  NS_ENSURE_SUCCESS_VOID(rv);
+
+  rv = prefSvc->GetDefaultBranch(nullptr, getter_AddRefs(prefBranch));
+  NS_ENSURE_SUCCESS_VOID(rv);
+
+  nsCString channel("default");
+  rv = prefBranch->GetCharPref("app.update.channel", channel);
+  NS_ENSURE_SUCCESS_VOID(rv);
+
+  nsID uuid;
+  rv = nsID::GenerateUUIDInPlace(uuid);
+  NS_ENSURE_SUCCESS_VOID(rv);
+
+  nsCString arch("null");
+  nsCOMPtr<nsIPropertyBag2> sysInfo =
+      do_GetService("@mozilla.org/system-info;1");
+  NS_ENSURE_TRUE_VOID(sysInfo);
+  sysInfo->GetPropertyAsACString(u"arch"_ns, arch);
+
+  time_t now;
+  time(&now);
+  char date[sizeof "YYYY-MM-DDThh:mm:ss.000Z"];
+  strftime(date, sizeof date, "%FT%T.000Z", gmtime(&now));
+
+  NSID_TrimBracketsASCII pingId(uuid);
+  constexpr auto pingType = "downgrade"_ns;
+
+  int32_t pos = aLastVersion.Find("_");
+  if (pos == kNotFound) {
+    return;
+  }
+
+  const nsDependentCSubstring lastVersion = Substring(aLastVersion, 0, pos);
+  const nsDependentCSubstring lastBuildId =
+      Substring(aLastVersion, pos + 1, 14);
+
+  nsPrintfCString url("%s/submit/telemetry/%s/%s/%s/%s/%s/%s?v=%d",
+                      server.get(), PromiseFlatCString(pingId).get(),
+                      pingType.get(), (const char*)gAppData->name,
+                      (const char*)gAppData->version, channel.get(),
+                      (const char*)gAppData->buildID,
+                      TELEMETRY_PING_FORMAT_VERSION);
+
+  nsCOMPtr<nsIFile> pingFile;
+  rv = NS_GetSpecialDirectory(XRE_USER_APP_DATA_DIR, getter_AddRefs(pingFile));
+  NS_ENSURE_SUCCESS_VOID(rv);
+  rv = pingFile->Append(u"Pending Pings"_ns);
+  NS_ENSURE_SUCCESS_VOID(rv);
+  rv = pingFile->Create(nsIFile::DIRECTORY_TYPE, 0755);
+  if (NS_FAILED(rv) && rv != NS_ERROR_FILE_ALREADY_EXISTS) {
+    return;
+  }
+  rv = pingFile->Append(NS_ConvertUTF8toUTF16(pingId));
+  NS_ENSURE_SUCCESS_VOID(rv);
+
+  nsCOMPtr<nsIFile> pingSender;
+  rv = NS_GetSpecialDirectory(NS_GRE_BIN_DIR, getter_AddRefs(pingSender));
+  NS_ENSURE_SUCCESS_VOID(rv);
+#  ifdef XP_WIN
+  pingSender->Append(u"pingsender.exe"_ns);
+#  else
+  pingSender->Append(u"pingsender"_ns);
+#  endif
+
+  bool exists;
+  rv = pingSender->Exists(&exists);
+  NS_ENSURE_SUCCESS_VOID(rv);
+  if (!exists) {
+    return;
+  }
+
+  FILE* file;
+  rv = pingFile->OpenANSIFileDesc("w", &file);
+  NS_ENSURE_SUCCESS_VOID(rv);
+
+  JSONWriter w(MakeUnique<FileWriteFunc>(file));
+  w.Start();
+  {
+    w.StringProperty("type",
+                     Span<const char>(pingType.Data(), pingType.Length()));
+    w.StringProperty("id", PromiseFlatCString(pingId));
+    w.StringProperty("creationDate", MakeStringSpan(date));
+    w.IntProperty("version", TELEMETRY_PING_FORMAT_VERSION);
+    w.StringProperty("clientId", clientId);
+    w.StartObjectProperty("application");
+    {
+      w.StringProperty("architecture", arch);
+      w.StringProperty(
+          "buildId",
+          MakeStringSpan(static_cast<const char*>(gAppData->buildID)));
+      w.StringProperty(
+          "name", MakeStringSpan(static_cast<const char*>(gAppData->name)));
+      w.StringProperty(
+          "version",
+          MakeStringSpan(static_cast<const char*>(gAppData->version)));
+      w.StringProperty("displayVersion",
+                       MOZ_STRINGIFY(MOZ_APP_VERSION_DISPLAY));
+      w.StringProperty(
+          "vendor", MakeStringSpan(static_cast<const char*>(gAppData->vendor)));
+      w.StringProperty("platformVersion", gToolkitVersion);
+#  ifdef TARGET_XPCOM_ABI
+      w.StringProperty("xpcomAbi", TARGET_XPCOM_ABI);
+#  else
+      w.StringProperty("xpcomAbi", "unknown");
+#  endif
+      w.StringProperty("channel", channel);
+    }
+    w.EndObject();
+    w.StartObjectProperty("payload");
+    {
+      w.StringProperty("lastVersion", PromiseFlatCString(lastVersion));
+      w.StringProperty("lastBuildId", PromiseFlatCString(lastBuildId));
+      w.BoolProperty("hasSync", aHasSync);
+      w.IntProperty("button", aButton);
+    }
+    w.EndObject();
+  }
+  w.End();
+
+  fclose(file);
+
+  PathString filePath = pingFile->NativePath();
+  const filesystem::Path::value_type* args[2];
+#  ifdef XP_WIN
+  nsString urlw = NS_ConvertUTF8toUTF16(url);
+  args[0] = urlw.get();
+#  else
+  args[0] = url.get();
+#  endif
+  args[1] = filePath.get();
+
+  nsCOMPtr<nsIProcess> process =
+      do_CreateInstance("@mozilla.org/process/util;1");
+  NS_ENSURE_TRUE_VOID(process);
+  process->Init(pingSender);
+  process->SetStartHidden(true);
+  process->SetNoShell(true);
+
+#  ifdef XP_WIN
+  process->Runw(false, args, 2);
+#  else
+  process->Run(false, args, 2);
+#  endif
+}
+
+static const char kProfileDowngradeURL[] =
+    "chrome://mozapps/content/profile/profileDowngrade.xhtml";
+
+static ReturnAbortOnError CheckDowngrade(nsIFile* aProfileDir,
+                                         nsINativeAppSupport* aNative,
+                                         nsIToolkitProfileService* aProfileSvc,
+                                         const nsCString& aLastVersion) {
+  int32_t result = 0;
+  nsresult rv;
+
+  {
+    if (gfxPlatform::IsHeadless()) {
+      // TODO: make a way to turn off all dialogs when headless.
+      Output(true,
+             "This profile was last used with a newer version of this "
+             "application. Please create a new profile.\n");
+      return NS_ERROR_ABORT;
+    }
+
+    ScopedXPCOMStartup xpcom;
+    rv = xpcom.Initialize();
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    rv = xpcom.SetWindowCreator(aNative);
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    {  // extra scoping is needed so we release these components before xpcom
+       // shutdown
+      bool hasSync = false;
+      nsCOMPtr<nsIPrefService> prefSvc =
+          do_GetService("@mozilla.org/preferences-service;1");
+      NS_ENSURE_TRUE(prefSvc, rv);
+
+      nsCOMPtr<nsIFile> prefsFile;
+      rv = aProfileDir->Clone(getter_AddRefs(prefsFile));
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      rv = prefsFile->Append(u"prefs.js"_ns);
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      rv = prefSvc->ReadUserPrefsFromFile(prefsFile);
+      if (NS_SUCCEEDED(rv)) {
+        nsCOMPtr<nsIPrefBranch> prefBranch = do_QueryInterface(prefSvc);
+
+        rv = prefBranch->PrefHasUserValue("services.sync.username", &hasSync);
+        NS_ENSURE_SUCCESS(rv, rv);
+      }
+
+      nsCOMPtr<nsIWindowWatcher> windowWatcher =
+          do_GetService(NS_WINDOWWATCHER_CONTRACTID);
+      NS_ENSURE_TRUE(windowWatcher, NS_ERROR_ABORT);
+
+      nsCOMPtr<nsIAppStartup> appStartup(components::AppStartup::Service());
+      NS_ENSURE_TRUE(appStartup, NS_ERROR_FAILURE);
+
+      nsCOMPtr<nsIDialogParamBlock> paramBlock =
+          do_CreateInstance(NS_DIALOGPARAMBLOCK_CONTRACTID);
+      NS_ENSURE_TRUE(paramBlock, NS_ERROR_ABORT);
+
+      uint8_t flags = 0;
+      if (hasSync) {
+        flags |= nsIToolkitProfileService::hasSync;
+      }
+
+      paramBlock->SetInt(0, flags);
+
+      nsAutoCString features("centerscreen,chrome,modal,titlebar");
+      // If we're launching a private browsing window make sure to set that
+      // feature for the Profile Manager window as well, so it groups correctly
+      // on the Windows taskbar.
+      if (CheckArgExists("private-window") == ARG_FOUND) {
+        features.AppendLiteral(",private");
+      }
+      nsCOMPtr<mozIDOMWindowProxy> newWindow;
+      rv = windowWatcher->OpenWindow(
+          nullptr, nsDependentCString(kProfileDowngradeURL), "_blank"_ns,
+          features, paramBlock, getter_AddRefs(newWindow));
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      paramBlock->GetInt(1, &result);
+
+      SubmitDowngradeTelemetry(aLastVersion, hasSync, result);
+    }
+  }
+
+  if (result == nsIToolkitProfileService::createNewProfile) {
+    // Create a new profile and start it.
+    nsCString profileName;
+    profileName.AssignLiteral("default");
+#  ifdef MOZ_DEDICATED_PROFILES
+    profileName.Append("-" MOZ_STRINGIFY(MOZ_UPDATE_CHANNEL));
+#  endif
+    nsCOMPtr<nsIToolkitProfile> newProfile;
+    rv = aProfileSvc->CreateUniqueProfile(nullptr, profileName,
+                                          getter_AddRefs(newProfile));
+    NS_ENSURE_SUCCESS(rv, rv);
+    rv = aProfileSvc->SetDefaultProfile(newProfile);
+    NS_ENSURE_SUCCESS(rv, rv);
+    rv = aProfileSvc->Flush();
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    nsCOMPtr<nsIFile> profD, profLD;
+    rv = newProfile->GetRootDir(getter_AddRefs(profD));
+    NS_ENSURE_SUCCESS(rv, rv);
+    rv = newProfile->GetLocalDir(getter_AddRefs(profLD));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    SaveFileToEnv("XRE_PROFILE_PATH", profD);
+    SaveFileToEnv("XRE_PROFILE_LOCAL_PATH", profLD);
+
+    return LaunchChild(false, true);
+  }
+
+  // Cancel
+  return NS_ERROR_ABORT;
+}
+#endif
+
+/**
+ * Extracts the various parts of a compatibility version string.
+ *
+ * Compatibility versions are of the form
+ * "<appversion>_<appbuildid>/<platformbuildid>". The toolkit version comparator
+ * can only handle 32-bit numbers and in the normal case build IDs are larger
+ * than this. So if the build ID is numeric we split it into two version parts.
+ */
+static void ExtractCompatVersionInfo(const nsACString& aCompatVersion,
+                                     nsACString& aAppVersion,
+                                     nsACString& aAppBuildID) {
+  int32_t underscorePos = aCompatVersion.FindChar('_');
+  int32_t slashPos = aCompatVersion.FindChar('/');
+
+  if (underscorePos == kNotFound || slashPos == kNotFound ||
+      slashPos < underscorePos) {
+    NS_WARNING(
+        "compatibility.ini Version string does not match the expected format.");
+
+    // Fall back to just using the entire string as the version.
+    aAppVersion = aCompatVersion;
+    aAppBuildID.Truncate(0);
+    return;
+  }
+
+  aAppVersion = Substring(aCompatVersion, 0, underscorePos);
+  aAppBuildID = Substring(aCompatVersion, underscorePos + 1,
+                          slashPos - (underscorePos + 1));
+}
+
+/**
+ * Compares the provided compatibility versions. Returns 0 if they match,
+ * < 0 if the new version is considered an upgrade from the old version and
+ * > 0 if the new version is considered a downgrade from the old version.
+ */
+int32_t CompareCompatVersions(const nsACString& aOldCompatVersion,
+                              const nsACString& aNewCompatVersion) {
+  // Hardcode the case where the last run was in safe mode (Bug 1556612). We
+  // cannot tell if this is a downgrade or not so just assume it isn't and let
+  // the user proceed.
+  if (aOldCompatVersion.EqualsLiteral("Safe Mode")) {
+    return -1;
+  }
+
+  // Extract the major version part from the version string and only use that
+  // for version comparison.
+  int32_t index = aOldCompatVersion.FindChar('.');
+  const nsACString& oldMajorVersion = Substring(
+      aOldCompatVersion, 0, index < 0 ? aOldCompatVersion.Length() : index);
+  index = aNewCompatVersion.FindChar('.');
+  const nsACString& newMajorVersion = Substring(
+      aNewCompatVersion, 0, index < 0 ? aNewCompatVersion.Length() : index);
+
+  return CompareVersions(PromiseFlatCString(oldMajorVersion).get(),
+                         PromiseFlatCString(newMajorVersion).get());
+}
+
+/**
+ * Checks the compatibility.ini file to see if we have updated our application
+ * or otherwise invalidated our caches. If the application has been updated,
+ * we return false; otherwise, we return true.
+ *
+ * We also write the status of the caches (valid/invalid) into the return param
+ * aCachesOK. The aCachesOK is always invalid if the application has been
+ * updated.
+ *
+ * Finally, aIsDowngrade is set to true if the current application is older
+ * than that previously used by the profile.
+ */
+static bool CheckCompatibility(nsIFile* aProfileDir, const nsCString& aVersion,
+                               const nsCString& aOSABI, nsIFile* aXULRunnerDir,
+                               nsIFile* aAppDir, nsIFile* aFlagFile,
+                               bool* aCachesOK, bool* aIsDowngrade,
+                               nsCString& aLastVersion) {
+  *aCachesOK = false;
+  *aIsDowngrade = false;
+  gLastAppVersion.SetIsVoid(true);
+  gLastAppBuildID.SetIsVoid(true);
+
+  nsCOMPtr<nsIFile> file;
+  aProfileDir->Clone(getter_AddRefs(file));
+  if (!file) return false;
+  file->AppendNative(FILE_COMPATIBILITY_INFO);
+
+  nsINIParser parser;
+  nsresult rv = parser.Init(file);
+  if (NS_FAILED(rv)) return false;
+
+  rv = parser.GetString("Compatibility", "LastVersion", aLastVersion);
+  if (NS_FAILED(rv)) {
+    return false;
+  }
+
+  if (!aLastVersion.Equals(aVersion)) {
+    // The version is not the same. Whether it's a downgrade depends on an
+    // actual comparison:
+    *aIsDowngrade = 0 < CompareCompatVersions(aLastVersion, aVersion);
+    ExtractCompatVersionInfo(aLastVersion, gLastAppVersion, gLastAppBuildID);
+    return false;
+  }
+
+  // If we get here, the version matched, but there may still be other
+  // differences between us and the build that the profile last ran under.
+
+  gLastAppVersion.Assign(gAppData->version);
+  gLastAppBuildID.Assign(gAppData->buildID);
+
+  nsAutoCString buf;
+  rv = parser.GetString("Compatibility", "LastOSABI", buf);
+  if (NS_FAILED(rv) || !aOSABI.Equals(buf)) return false;
+
+  rv = parser.GetString("Compatibility", "LastPlatformDir", buf);
+  if (NS_FAILED(rv)) return false;
+
+  nsCOMPtr<nsIFile> lf;
+  rv = NS_NewNativeLocalFile(""_ns, false, getter_AddRefs(lf));
+  if (NS_FAILED(rv)) return false;
+
+  rv = lf->SetPersistentDescriptor(buf);
+  if (NS_FAILED(rv)) return false;
+
+  bool eq;
+  rv = lf->Equals(aXULRunnerDir, &eq);
+  if (NS_FAILED(rv) || !eq) return false;
+
+  if (aAppDir) {
+    rv = parser.GetString("Compatibility", "LastAppDir", buf);
+    if (NS_FAILED(rv)) return false;
+
+    rv = NS_NewNativeLocalFile(""_ns, false, getter_AddRefs(lf));
+    if (NS_FAILED(rv)) return false;
+
+    rv = lf->SetPersistentDescriptor(buf);
+    if (NS_FAILED(rv)) return false;
+
+    rv = lf->Equals(aAppDir, &eq);
+    if (NS_FAILED(rv) || !eq) return false;
+  }
+
+  // If we see this flag, caches are invalid.
+  rv = parser.GetString("Compatibility", "InvalidateCaches", buf);
+  *aCachesOK = (NS_FAILED(rv) || !buf.EqualsLiteral("1"));
+
+  bool purgeCaches = false;
+  if (aFlagFile && NS_SUCCEEDED(aFlagFile->Exists(&purgeCaches)) &&
+      purgeCaches) {
+    *aCachesOK = false;
+  }
+
+  return true;
+}
+
+void BuildCompatVersion(const char* aAppVersion, const char* aAppBuildID,
+                        const char* aToolkitBuildID, nsACString& aBuf) {
+  aBuf.Assign(aAppVersion);
+  aBuf.Append('_');
+  aBuf.Append(aAppBuildID);
+  aBuf.Append('/');
+  aBuf.Append(aToolkitBuildID);
+}
+
+static void BuildVersion(nsCString& aBuf) {
+  BuildCompatVersion(gAppData->version, gAppData->buildID, gToolkitBuildID,
+                     aBuf);
+}
+
+static void WriteVersion(nsIFile* aProfileDir, const nsCString& aVersion,
+                         const nsCString& aOSABI, nsIFile* aXULRunnerDir,
+                         nsIFile* aAppDir, bool invalidateCache) {
+  nsCOMPtr<nsIFile> file;
+  aProfileDir->Clone(getter_AddRefs(file));
+  if (!file) return;
+  file->AppendNative(FILE_COMPATIBILITY_INFO);
+
+  nsAutoCString platformDir;
+  Unused << aXULRunnerDir->GetPersistentDescriptor(platformDir);
+
+  nsAutoCString appDir;
+  if (aAppDir) Unused << aAppDir->GetPersistentDescriptor(appDir);
+
+  PRFileDesc* fd;
+  nsresult rv = file->OpenNSPRFileDesc(PR_WRONLY | PR_CREATE_FILE | PR_TRUNCATE,
+                                       0600, &fd);
+  if (NS_FAILED(rv)) {
+    NS_ERROR("could not create output stream");
+    return;
+  }
+
+  static const char kHeader[] = "[Compatibility]" NS_LINEBREAK "LastVersion=";
+
+  PR_Write(fd, kHeader, sizeof(kHeader) - 1);
+  PR_Write(fd, aVersion.get(), aVersion.Length());
+
+  static const char kOSABIHeader[] = NS_LINEBREAK "LastOSABI=";
+  PR_Write(fd, kOSABIHeader, sizeof(kOSABIHeader) - 1);
+  PR_Write(fd, aOSABI.get(), aOSABI.Length());
+
+  static const char kPlatformDirHeader[] = NS_LINEBREAK "LastPlatformDir=";
+
+  PR_Write(fd, kPlatformDirHeader, sizeof(kPlatformDirHeader) - 1);
+  PR_Write(fd, platformDir.get(), platformDir.Length());
+
+  static const char kAppDirHeader[] = NS_LINEBREAK "LastAppDir=";
+  if (aAppDir) {
+    PR_Write(fd, kAppDirHeader, sizeof(kAppDirHeader) - 1);
+    PR_Write(fd, appDir.get(), appDir.Length());
+  }
+
+  static const char kInvalidationHeader[] = NS_LINEBREAK "InvalidateCaches=1";
+  if (invalidateCache)
+    PR_Write(fd, kInvalidationHeader, sizeof(kInvalidationHeader) - 1);
+
+  static const char kNL[] = NS_LINEBREAK;
+  PR_Write(fd, kNL, sizeof(kNL) - 1);
+
+  PR_Close(fd);
+}
+
+/**
+ * Returns true if the startup cache file was successfully removed.
+ * Returns false if file->Clone fails at any point (OOM) or if unable
+ * to remove the startup cache file. Note in particular the return value
+ * is unaffected by a failure to remove extensions.ini
+ */
+static bool RemoveComponentRegistries(nsIFile* aProfileDir,
+                                      nsIFile* aLocalProfileDir,
+                                      bool aRemoveEMFiles) {
+  nsCOMPtr<nsIFile> file;
+  aProfileDir->Clone(getter_AddRefs(file));
+  if (!file) return false;
+
+  if (aRemoveEMFiles) {
+    file->SetNativeLeafName("extensions.ini"_ns);
+    file->Remove(false);
+  }
+
+  aLocalProfileDir->Clone(getter_AddRefs(file));
+  if (!file) return false;
+
+  file->AppendNative("startupCache"_ns);
+  nsresult rv = file->Remove(true);
+  return NS_SUCCEEDED(rv) || rv == NS_ERROR_FILE_NOT_FOUND;
+}
+
+// When we first initialize the crash reporter we don't have a profile,
+// so we set the minidump path to $TEMP.  Once we have a profile,
+// we set it to $PROFILE/minidumps, creating the directory
+// if needed.
+static void MakeOrSetMinidumpPath(nsIFile* profD) {
+  nsCOMPtr<nsIFile> dumpD;
+  profD->Clone(getter_AddRefs(dumpD));
+
+  if (dumpD) {
+    bool fileExists;
+    // XXX: do some more error checking here
+    dumpD->Append(u"minidumps"_ns);
+    dumpD->Exists(&fileExists);
+    if (!fileExists) {
+      nsresult rv = dumpD->Create(nsIFile::DIRECTORY_TYPE, 0700);
+      NS_ENSURE_SUCCESS_VOID(rv);
+    }
+
+    nsAutoString pathStr;
+    if (NS_SUCCEEDED(dumpD->GetPath(pathStr)))
+      CrashReporter::SetMinidumpPath(pathStr);
+  }
+}
+
+const XREAppData* gAppData = nullptr;
+
+/**
+ * NSPR will search for the "nspr_use_zone_allocator" symbol throughout
+ * the process and use it to determine whether the application defines its own
+ * memory allocator or not.
+ *
+ * Since most applications (e.g. Firefox and Thunderbird) don't use any special
+ * allocators and therefore don't define this symbol, NSPR must search the
+ * entire process, which reduces startup performance.
+ *
+ * By defining the symbol here, we can avoid the wasted lookup and hopefully
+ * improve startup performance.
+ */
+NS_VISIBILITY_DEFAULT PRBool nspr_use_zone_allocator = PR_FALSE;
+
+#ifdef CAIRO_HAS_DWRITE_FONT
+
+#  include <dwrite.h>
+#  include "nsWindowsHelpers.h"
+
+#  ifdef DEBUG_DWRITE_STARTUP
+
+#    define LOGREGISTRY(msg) LogRegistryEvent(msg)
+
+// for use when monitoring process
+static void LogRegistryEvent(const wchar_t* msg) {
+  HKEY dummyKey;
+  HRESULT hr;
+  wchar_t buf[512];
+
+  wsprintf(buf, L" log %s", msg);
+  hr = RegOpenKeyEx(HKEY_LOCAL_MACHINE, buf, 0, KEY_READ, &dummyKey);
+  if (SUCCEEDED(hr)) {
+    RegCloseKey(dummyKey);
+  }
+}
+#  else
+
+#    define LOGREGISTRY(msg)
+
+#  endif
+
+static DWORD WINAPI InitDwriteBG(LPVOID lpdwThreadParam) {
+  SetThreadPriority(GetCurrentThread(), THREAD_MODE_BACKGROUND_BEGIN);
+  LOGREGISTRY(L"loading dwrite.dll");
+  HMODULE dwdll = LoadLibrarySystem32(L"dwrite.dll");
+  if (dwdll) {
+    decltype(DWriteCreateFactory)* createDWriteFactory =
+        (decltype(DWriteCreateFactory)*)GetProcAddress(dwdll,
+                                                       "DWriteCreateFactory");
+    if (createDWriteFactory) {
+      LOGREGISTRY(L"creating dwrite factory");
+      IDWriteFactory* factory;
+      HRESULT hr = createDWriteFactory(DWRITE_FACTORY_TYPE_SHARED,
+                                       __uuidof(IDWriteFactory),
+                                       reinterpret_cast<IUnknown**>(&factory));
+      if (SUCCEEDED(hr)) {
+        LOGREGISTRY(L"dwrite factory done");
+        factory->Release();
+        LOGREGISTRY(L"freed factory");
+      } else {
+        LOGREGISTRY(L"failed to create factory");
+      }
+    }
+  }
+  SetThreadPriority(GetCurrentThread(), THREAD_MODE_BACKGROUND_END);
+  return 0;
+}
+#endif
+
+#include "GeckoProfiler.h"
+#include "ProfilerControl.h"
+
+// Encapsulates startup and shutdown state for XRE_main
+class XREMain {
+ public:
+  XREMain() = default;
+
+  ~XREMain() {
+    mScopedXPCOM = nullptr;
+    mAppData = nullptr;
+  }
+
+  int XRE_main(int argc, char* argv[], const BootstrapConfig& aConfig);
+  int XRE_mainInit(bool* aExitFlag);
+  int XRE_mainStartup(bool* aExitFlag);
+  nsresult XRE_mainRun();
+
+  bool CheckLastStartupWasCrash();
+
+  nsCOMPtr<nsINativeAppSupport> mNativeApp;
+  RefPtr<nsToolkitProfileService> mProfileSvc;
+  nsCOMPtr<nsIFile> mProfD;
+  nsCOMPtr<nsIFile> mProfLD;
+  nsCOMPtr<nsIProfileLock> mProfileLock;
+#if defined(MOZ_HAS_REMOTE)
+  RefPtr<nsRemoteService> mRemoteService;
+#endif
+
+  UniquePtr<ScopedXPCOMStartup> mScopedXPCOM;
+  UniquePtr<XREAppData> mAppData;
+
+  nsXREDirProvider mDirProvider;
+
+#ifdef MOZ_WIDGET_GTK
+  nsAutoCString mXDGActivationToken;
+  nsAutoCString mDesktopStartupID;
+#endif
+
+  bool mStartOffline = false;
+#if defined(MOZ_HAS_REMOTE)
+  bool mDisableRemoteClient = false;
+  bool mDisableRemoteServer = false;
+#endif
+};
+
+#if defined(XP_UNIX) && !defined(ANDROID)
+static SmprintfPointer FormatUid(uid_t aId) {
+  if (const auto pw = getpwuid(aId)) {
+    return mozilla::Smprintf("%s", pw->pw_name);
+  }
+  return mozilla::Smprintf("uid %d", static_cast<int>(aId));
+}
+
+// Bug 1323302: refuse to run under sudo or similar.
+static bool CheckForUserMismatch() {
+  static char const* const kVars[] = {
+      "HOME",
+#  ifdef MOZ_WIDGET_GTK
+      "XDG_RUNTIME_DIR",
+#  endif
+#  ifdef MOZ_X11
+      "XAUTHORITY",
+#  endif
+  };
+
+  const uid_t euid = geteuid();
+  if (euid != 0) {
+    // On Linux it's possible to have superuser capabilities with a
+    // nonzero uid, but anyone who knows enough to make that happen
+    // probably knows enough to debug the resulting problems.
+    // Otherwise, a non-root user can't cause the problems we're
+    // concerned about.
+    return false;
+  }
+
+  for (const auto var : kVars) {
+    if (const auto path = PR_GetEnv(var)) {
+      struct stat st;
+      if (stat(path, &st) == 0) {
+        if (st.st_uid != euid) {
+          const auto owner = FormatUid(st.st_uid);
+          Output(true,
+                 "Running " MOZ_APP_DISPLAYNAME
+                 " as root in a regular"
+                 " user's session is not supported.  ($%s is %s which is"
+                 " owned by %s.)\n",
+                 var, path, owner.get());
+          return true;
+        }
+      }
+    }
+  }
+  return false;
+}
+#else  // !XP_UNIX || ANDROID
+static bool CheckForUserMismatch() { return false; }
+#endif
+
+void mozilla::startup::IncreaseDescriptorLimits() {
+#ifdef XP_UNIX
+  // Increase the fd limit to accomodate IPC resources like shared memory.
+  // See also the Darwin case in config/external/nspr/pr/moz.build
+  static const rlim_t kFDs = 4096;
+  struct rlimit rlim;
+
+  if (getrlimit(RLIMIT_NOFILE, &rlim) != 0) {
+    Output(false, "getrlimit: %s\n", strerror(errno));
+    return;
+  }
+  // Don't decrease the limit if it's already high enough, but don't
+  // try to go over the hard limit.  (RLIM_INFINITY isn't required to
+  // be the numerically largest rlim_t, so don't assume that.)
+  if (rlim.rlim_cur != RLIM_INFINITY && rlim.rlim_cur < kFDs &&
+      rlim.rlim_cur < rlim.rlim_max) {
+    if (rlim.rlim_max != RLIM_INFINITY && rlim.rlim_max < kFDs) {
+      rlim.rlim_cur = rlim.rlim_max;
+    } else {
+      rlim.rlim_cur = kFDs;
+    }
+    if (setrlimit(RLIMIT_NOFILE, &rlim) != 0) {
+      Output(false, "setrlimit: %s\n", strerror(errno));
+    }
+  }
+#endif
+}
+
+#ifdef XP_WIN
+
+static uint32_t GetMicrocodeVersionByVendor(HKEY key, DWORD upper,
+                                            DWORD lower) {
+  WCHAR data[13];  // The CPUID vendor string is 12 characters long plus null
+  DWORD len = sizeof(data);
+  DWORD vtype;
+
+  if (RegQueryValueExW(key, L"VendorIdentifier", nullptr, &vtype,
+                       reinterpret_cast<LPBYTE>(data), &len) == ERROR_SUCCESS) {
+    if (wcscmp(L"GenuineIntel", data) == 0) {
+      // Intel reports the microcode version in the upper 32 bits of the MSR
+      return upper;
+    }
+
+    if (wcscmp(L"AuthenticAMD", data) == 0) {
+      // AMD reports the microcode version in the lower 32 bits of the MSR
+      return lower;
+    }
+
+    // Unknown CPU vendor, return whatever half is non-zero
+    return lower ? lower : upper;
+  }
+
+  return 0;  // No clue
+}
+
+#endif  // XP_WIN
+
+static void MaybeAddCPUMicrocodeCrashAnnotation() {
+#ifdef XP_WIN
+  // Add CPU microcode version to the crash report as "CPUMicrocodeVersion".
+  // It feels like this code may belong in nsSystemInfo instead.
+  uint32_t cpuUpdateRevision = 0;
+  HKEY key;
+  static const WCHAR keyName[] =
+      L"HARDWARE\\DESCRIPTION\\System\\CentralProcessor\\0";
+
+  if (RegOpenKeyEx(HKEY_LOCAL_MACHINE, keyName, 0, KEY_QUERY_VALUE, &key) ==
+      ERROR_SUCCESS) {
+    DWORD updateRevision[2];
+    DWORD len = sizeof(updateRevision);
+    DWORD vtype;
+
+    // Windows 7 uses "Update Signature", 8 uses "Update Revision".
+    // For AMD CPUs, "CurrentPatchLevel" is sometimes used.
+    // Take the first one we find.
+    LPCWSTR choices[] = {L"Update Signature", L"Update Revision",
+                         L"CurrentPatchLevel"};
+    for (const auto& oneChoice : choices) {
+      if (RegQueryValueExW(key, oneChoice, nullptr, &vtype,
+                           reinterpret_cast<LPBYTE>(updateRevision),
+                           &len) == ERROR_SUCCESS) {
+        if (vtype == REG_BINARY && len == sizeof(updateRevision)) {
+          cpuUpdateRevision = GetMicrocodeVersionByVendor(
+              key, updateRevision[1], updateRevision[0]);
+          break;
+        }
+
+        if (vtype == REG_DWORD && len == sizeof(updateRevision[0])) {
+          cpuUpdateRevision = static_cast<int>(updateRevision[0]);
+          break;
+        }
+      }
+    }
+  }
+
+  if (cpuUpdateRevision > 0) {
+    CrashReporter::AnnotateCrashReport(
+        CrashReporter::Annotation::CPUMicrocodeVersion,
+        nsPrintfCString("0x%" PRIx32, cpuUpdateRevision));
+  }
+#endif
+}
+
+#if defined(MOZ_BACKGROUNDTASKS)
+static void SetupConsoleForBackgroundTask(
+    const nsCString& aBackgroundTaskName) {
+  // We do not suppress output on Windows because:
+  // 1. Background task subprocesses launched via LaunchApp() does not attach to
+  //    the console.
+  // 2. Suppressing output intermittently causes failures on when running
+  //    multiple tasks (see bug 1831631)
+#  ifndef XP_WIN
+  if (BackgroundTasks::IsNoOutputTaskName(aBackgroundTaskName) &&
+      !CheckArg("attach-console") &&
+      !EnvHasValue("MOZ_BACKGROUNDTASKS_IGNORE_NO_OUTPUT")) {
+    // Suppress output, somewhat crudely.  We need to suppress stderr as well
+    // as stdout because assertions, of which there are many, write to stderr.
+    Unused << freopen("/dev/null", "w", stdout);
+    Unused << freopen("/dev/null", "w", stderr);
+    return;
+  }
+#  endif
+  printf_stderr("*** You are running in background task mode. ***\n");
+}
+#endif
+
+/*
+ * XRE_mainInit - Initial setup and command line parameter processing.
+ * Main() will exit early if either return value != 0 or if aExitFlag is
+ * true.
+ */
+int XREMain::XRE_mainInit(bool* aExitFlag) {
+  if (!aExitFlag) return 1;
+  *aExitFlag = false;
+
+  atexit(UnexpectedExit);
+  auto expectedShutdown = mozilla::MakeScopeExit([&] { MozExpectedExit(); });
+
+  StartupTimeline::Record(StartupTimeline::MAIN);
+
+  if (CheckForUserMismatch()) {
+    return 1;
+  }
+
+#ifdef XP_MACOSX
+  mozilla::MacAutoreleasePool pool;
+
+  DisableAppNap();
+#endif
+
+#ifdef MOZ_BACKGROUNDTASKS
+  Maybe<nsCString> backgroundTask = Nothing();
+  const char* backgroundTaskName = nullptr;
+  if (ARG_FOUND ==
+      CheckArg("backgroundtask", &backgroundTaskName, CheckArgFlag::None)) {
+    backgroundTask = Some(backgroundTaskName);
+
+    SetupConsoleForBackgroundTask(backgroundTask.ref());
+  }
+
+  BackgroundTasks::Init(backgroundTask);
+#endif
+
+#ifndef ANDROID
+  if (PR_GetEnv("MOZ_RUN_GTEST")
+#  ifdef FUZZING
+      || PR_GetEnv("FUZZER")
+#  endif
+#  ifdef MOZ_BACKGROUNDTASKS
+      || BackgroundTasks::IsBackgroundTaskMode()
+#  endif
+  ) {
+    // Enable headless mode and assert that it worked, since gfxPlatform
+    // uses a static bool set after the first call to `IsHeadless`.
+    // Note: Android gtests seem to require an Activity and fail to start
+    // with headless mode enabled.
+    PR_SetEnv("MOZ_HEADLESS=1");
+    MOZ_ASSERT(gfxPlatform::IsHeadless());
+  }
+#endif  // ANDROID
+
+  if (PR_GetEnv("MOZ_CHAOSMODE")) {
+    ChaosFeature feature = ChaosFeature::Any;
+    long featureInt = strtol(PR_GetEnv("MOZ_CHAOSMODE"), nullptr, 16);
+    if (featureInt) {
+      // NOTE: MOZ_CHAOSMODE=0 or a non-hex value maps to Any feature.
+      feature = static_cast<ChaosFeature>(featureInt);
+    }
+    ChaosMode::SetChaosFeature(feature);
+  }
+
+  if (CheckArgExists("fxr")) {
+    gFxREmbedded = true;
+  }
+
+  if (ChaosMode::isActive(ChaosFeature::Any)) {
+    printf_stderr(
+        "*** You are running in chaos test mode. See ChaosMode.h. ***\n");
+  }
+
+  if (CheckArg("headless") || CheckArgExists("screenshot")) {
+    PR_SetEnv("MOZ_HEADLESS=1");
+  }
+
+  if (gfxPlatform::IsHeadless()) {
+#if defined(XP_WIN) || defined(MOZ_WIDGET_GTK) || defined(XP_MACOSX)
+    printf_stderr("*** You are running in headless mode.\n");
+#else
+    Output(
+        true,
+        "Error: headless mode is not currently supported on this platform.\n");
+    return 1;
+#endif
+
+#ifdef XP_MACOSX
+    // To avoid taking focus when running in headless mode immediately
+    // transition Firefox to a background application.
+    ProcessSerialNumber psn = {0, kCurrentProcess};
+    OSStatus transformStatus =
+        TransformProcessType(&psn, kProcessTransformToBackgroundApplication);
+    if (transformStatus != noErr) {
+      NS_ERROR("Failed to make process a background application.");
+      return 1;
+    }
+#endif
+  }
+
+  nsresult rv;
+  ArgResult ar;
+
+#ifdef DEBUG
+  if (PR_GetEnv("XRE_MAIN_BREAK")) NS_BREAK();
+#endif
+
+  mozilla::startup::IncreaseDescriptorLimits();
+
+  SetupErrorHandling(gArgv[0]);
+
+#ifdef CAIRO_HAS_DWRITE_FONT
+  {
+    // Bug 602792 - when DWriteCreateFactory is called the dwrite client dll
+    // starts the FntCache service if it isn't already running (it's set
+    // to manual startup by default in Windows 7 RTM).  Subsequent DirectWrite
+    // calls cause the IDWriteFactory object to communicate with the FntCache
+    // service with a timeout; if there's no response after the timeout, the
+    // DirectWrite client library will assume the service isn't around and do
+    // manual font file I/O on _all_ system fonts.  To avoid this, load the
+    // dwrite library and create a factory as early as possible so that the
+    // FntCache service is ready by the time it's needed.
+
+    CreateThread(nullptr, 0, &InitDwriteBG, nullptr, 0, nullptr);
+  }
+#endif
+
+#ifdef XP_UNIX
+  const char* home = PR_GetEnv("HOME");
+  if (!home || !*home) {
+    struct passwd* pw = getpwuid(geteuid());
+    if (!pw || !pw->pw_dir) {
+      Output(true, "Could not determine HOME directory");
+      return 1;
+    }
+    SaveWordToEnv("HOME", nsDependentCString(pw->pw_dir));
+  }
+#endif
+
+#ifdef MOZ_ACCESSIBILITY_ATK
+  // Suppress atk-bridge init at startup, until mozilla accessibility is
+  // initialized.  This works after gnome 2.24.2.
+  SaveToEnv("NO_AT_BRIDGE=1");
+#endif
+
+  // Check for application.ini overrides
+  const char* override = nullptr;
+  ar = CheckArg("override", &override);
+  if (ar == ARG_BAD) {
+    Output(true, "Incorrect number of arguments passed to --override");
+    return 1;
+  }
+  if (ar == ARG_FOUND) {
+    nsCOMPtr<nsIFile> overrideLF;
+    rv = XRE_GetFileFromPath(override, getter_AddRefs(overrideLF));
+    if (NS_FAILED(rv)) {
+      Output(true, "Error: unrecognized override.ini path.\n");
+      return 1;
+    }
+
+    rv = XRE_ParseAppData(overrideLF, *mAppData);
+    if (NS_FAILED(rv)) {
+      Output(true, "Couldn't read override.ini");
+      return 1;
+    }
+  }
+
+  // Check sanity and correctness of app data.
+
+  if (!mAppData->name) {
+    Output(true, "Error: App:Name not specified in application.ini\n");
+    return 1;
+  }
+  if (!mAppData->buildID) {
+    Output(true, "Error: App:BuildID not specified in application.ini\n");
+    return 1;
+  }
+
+  // XXX Originally ScopedLogging was here? Now it's in XRE_main above
+  // XRE_mainInit.
+
+  if (!mAppData->minVersion) {
+    Output(true, "Error: Gecko:MinVersion not specified in application.ini\n");
+    return 1;
+  }
+
+  if (!mAppData->maxVersion) {
+    // If no maxVersion is specified, we assume the app is only compatible
+    // with the initial preview release. Do not increment this number ever!
+    mAppData->maxVersion = "1.*";
+  }
+
+  if (mozilla::Version(mAppData->minVersion) > gToolkitVersion ||
+      mozilla::Version(mAppData->maxVersion) < gToolkitVersion) {
+    Output(true,
+           "Error: Platform version '%s' is not compatible with\n"
+           "minVersion >= %s\nmaxVersion <= %s\n",
+           (const char*)gToolkitVersion, (const char*)mAppData->minVersion,
+           (const char*)mAppData->maxVersion);
+    return 1;
+  }
+
+  rv = mDirProvider.Initialize(mAppData->directory, mAppData->xreDirectory);
+  if (NS_FAILED(rv)) return 1;
+
+  if (EnvHasValue("MOZ_CRASHREPORTER")) {
+    mAppData->flags |= NS_XRE_ENABLE_CRASH_REPORTER;
+  }
+
+  nsCOMPtr<nsIFile> xreBinDirectory;
+  xreBinDirectory = mDirProvider.GetGREBinDir();
+
+  if ((mAppData->flags & NS_XRE_ENABLE_CRASH_REPORTER) &&
+      NS_SUCCEEDED(CrashReporter::SetExceptionHandler(xreBinDirectory))) {
+    nsCOMPtr<nsIFile> file;
+    rv = nsXREDirProvider::GetUserAppDataDirectory(getter_AddRefs(file));
+    if (NS_SUCCEEDED(rv)) {
+      CrashReporter::SetUserAppDataDirectory(file);
+    }
+    if (mAppData->crashReporterURL)
+      CrashReporter::SetServerURL(
+          nsDependentCString(mAppData->crashReporterURL));
+
+    // We overwrite this once we finish starting up.
+    CrashReporter::AnnotateCrashReport(CrashReporter::Annotation::StartupCrash,
+                                       true);
+
+    // pass some basic info from the app data
+    if (mAppData->vendor)
+      CrashReporter::AnnotateCrashReport(CrashReporter::Annotation::Vendor,
+                                         nsDependentCString(mAppData->vendor));
+    if (mAppData->name)
+      CrashReporter::AnnotateCrashReport(CrashReporter::Annotation::ProductName,
+                                         nsDependentCString(mAppData->name));
+    if (mAppData->ID)
+      CrashReporter::AnnotateCrashReport(CrashReporter::Annotation::ProductID,
+                                         nsDependentCString(mAppData->ID));
+    if (mAppData->version)
+      CrashReporter::AnnotateCrashReport(CrashReporter::Annotation::Version,
+                                         nsDependentCString(mAppData->version));
+    if (mAppData->buildID)
+      CrashReporter::AnnotateCrashReport(CrashReporter::Annotation::BuildID,
+                                         nsDependentCString(mAppData->buildID));
+
+    nsDependentCString releaseChannel(MOZ_STRINGIFY(MOZ_UPDATE_CHANNEL));
+    CrashReporter::AnnotateCrashReport(
+        CrashReporter::Annotation::ReleaseChannel, releaseChannel);
+#ifdef MOZ_LINKER
+    CrashReporter::AnnotateCrashReport(
+        CrashReporter::Annotation::CrashAddressLikelyWrong,
+        IsSignalHandlingBroken());
+#endif
+
+#ifdef XP_WIN
+    nsAutoString appInitDLLs;
+    if (widget::WinUtils::GetAppInitDLLs(appInitDLLs)) {
+      CrashReporter::AnnotateCrashReport(CrashReporter::Annotation::AppInitDLLs,
+                                         NS_ConvertUTF16toUTF8(appInitDLLs));
+    }
+
+    nsString packageFamilyName = widget::WinUtils::GetPackageFamilyName();
+    if (StringBeginsWith(packageFamilyName, u"Mozilla."_ns) ||
+        StringBeginsWith(packageFamilyName, u"MozillaCorporation."_ns)) {
+      CrashReporter::AnnotateCrashReport(
+          CrashReporter::Annotation::WindowsPackageFamilyName,
+          NS_ConvertUTF16toUTF8(packageFamilyName));
+    }
+#endif
+
+    bool isBackgroundTaskMode = false;
+#ifdef MOZ_BACKGROUNDTASKS
+    Maybe<nsCString> backgroundTasks = BackgroundTasks::GetBackgroundTasks();
+    if (backgroundTasks.isSome()) {
+      isBackgroundTaskMode = true;
+      CrashReporter::AnnotateCrashReport(
+          CrashReporter::Annotation::BackgroundTaskName, backgroundTasks.ref());
+    }
+#endif
+    CrashReporter::AnnotateCrashReport(
+        CrashReporter::Annotation::BackgroundTaskMode, isBackgroundTaskMode);
+
+    CrashReporter::AnnotateCrashReport(CrashReporter::Annotation::HeadlessMode,
+                                       gfxPlatform::IsHeadless());
+
+    CrashReporter::SetRestartArgs(gArgc, gArgv);
+
+    // annotate other data (user id etc)
+    nsCOMPtr<nsIFile> userAppDataDir;
+    if (NS_SUCCEEDED(mDirProvider.GetUserAppDataDirectory(
+            getter_AddRefs(userAppDataDir)))) {
+      CrashReporter::SetupExtraData(userAppDataDir,
+                                    nsDependentCString(mAppData->buildID));
+
+      // see if we have a crashreporter-override.ini in the application
+      // directory
+      nsCOMPtr<nsIFile> overrideini;
+      if (NS_SUCCEEDED(
+              mDirProvider.GetAppDir()->Clone(getter_AddRefs(overrideini))) &&
+          NS_SUCCEEDED(
+              overrideini->AppendNative("crashreporter-override.ini"_ns))) {
+#ifdef XP_WIN
+        nsAutoString overridePathW;
+        overrideini->GetPath(overridePathW);
+        NS_ConvertUTF16toUTF8 overridePath(overridePathW);
+#else
+        nsAutoCString overridePath;
+        overrideini->GetNativePath(overridePath);
+#endif
+
+        SaveWordToEnv("MOZ_CRASHREPORTER_STRINGS_OVERRIDE", overridePath);
+      }
+    }
+  } else {
+    // We might have registered a runtime exception module very early in process
+    // startup to catch early crashes. This is before we have access to ini file
+    // data, so unregister here if it turns out the crash reporter is disabled.
+    CrashReporter::UnregisterRuntimeExceptionModule();
+  }
+
+#if defined(MOZ_SANDBOX) && defined(XP_WIN)
+  if (mAppData->sandboxBrokerServices) {
+    SandboxBroker::Initialize(mAppData->sandboxBrokerServices);
+  } else {
+#  if defined(MOZ_SANDBOX)
+    // If we're sandboxing content and we fail to initialize, then crashing here
+    // seems like the sensible option.
+    if (BrowserTabsRemoteAutostart()) {
+      MOZ_CRASH("Failed to initialize broker services, can't continue.");
+    }
+#  endif
+    // Otherwise just warn for the moment, as most things will work.
+    NS_WARNING(
+        "Failed to initialize broker services, sandboxed processes will "
+        "fail to start.");
+  }
+#endif
+
+#ifdef XP_MACOSX
+  // Set up ability to respond to system (Apple) events. This must occur before
+  // ProcessUpdates to ensure that links clicked in external applications aren't
+  // lost when updates are pending.
+  SetupMacApplicationDelegate(&gRestartedByOS);
+
+  if (EnvHasValue("MOZ_LAUNCHED_CHILD")) {
+    // This is needed, on relaunch, to force the OS to use the "Cocoa Dock
+    // API".  Otherwise the call to ReceiveNextEvent() below will make it
+    // use the "Carbon Dock API".  For more info see bmo bug 377166.
+    EnsureUseCocoaDockAPI();
+
+    // When the app relaunches, the original process exits.  This causes
+    // the dock tile to stop bouncing, lose the "running" triangle, and
+    // if the tile does not permanently reside in the Dock, even disappear.
+    // This can be confusing to the user, who is expecting the app to launch.
+    // Calling ReceiveNextEvent without requesting any event is enough to
+    // cause a dock tile for the child process to appear.
+    const EventTypeSpec kFakeEventList[] = {{INT_MAX, INT_MAX}};
+    EventRef event;
+    ::ReceiveNextEvent(GetEventTypeCount(kFakeEventList), kFakeEventList,
+                       kEventDurationNoWait, false, &event);
+  }
+
+  if (CheckArg("foreground")) {
+    // The original process communicates that it was in the foreground by
+    // adding this argument.  This new process, which is taking over for
+    // the old one, should make itself the active application.
+    ProcessSerialNumber psn;
+    if (::GetCurrentProcess(&psn) == noErr) ::SetFrontProcess(&psn);
+  }
+#endif
+
+  SaveToEnv("MOZ_LAUNCHED_CHILD=");
+
+  // On Windows, the -os-restarted command line switch lets us know when we are
+  // restarted via RegisterApplicationRestart. May be used for other OSes later.
+  if (CheckArg("os-restarted", nullptr, CheckArgFlag::RemoveArg) == ARG_FOUND) {
+    gRestartedByOS = true;
+  }
+
+  gRestartArgc = gArgc;
+  gRestartArgv =
+      (char**)malloc(sizeof(char*) * (gArgc + 1 + (override ? 2 : 0)));
+  if (!gRestartArgv) {
+    return 1;
+  }
+
+  int i;
+  for (i = 0; i < gArgc; ++i) {
+    gRestartArgv[i] = gArgv[i];
+  }
+
+  // Add the -override argument back (it is removed automatically be CheckArg)
+  // if there is one
+  if (override) {
+    gRestartArgv[gRestartArgc++] = const_cast<char*>("-override");
+    gRestartArgv[gRestartArgc++] = const_cast<char*>(override);
+  }
+
+  gRestartArgv[gRestartArgc] = nullptr;
+
+  Maybe<bool> safeModeRequested = IsSafeModeRequested(gArgc, gArgv);
+  if (!safeModeRequested) {
+    return 1;
+  }
+#ifdef MOZ_BACKGROUNDTASKS
+  if (BackgroundTasks::IsBackgroundTaskMode()) {
+    safeModeRequested = Some(false);
+
+    // Remove the --backgroundtask arg now that it has been saved in
+    // gRestartArgv.
+    const char* tmpBackgroundTaskName = nullptr;
+    Unused << CheckArg("backgroundtask", &tmpBackgroundTaskName,
+                       CheckArgFlag::RemoveArg);
+  }
+#endif
+
+  gSafeMode = safeModeRequested.value();
+
+  MaybeAddCPUMicrocodeCrashAnnotation();
+  CrashReporter::AnnotateCrashReport(CrashReporter::Annotation::SafeMode,
+                                     gSafeMode);
+
+#if defined(MOZ_HAS_REMOTE)
+  // Handle --no-remote and --new-instance command line arguments. Setup
+  // the environment to better accommodate other components and various
+  // restart scenarios.
+  ar = CheckArg("no-remote");
+  if (ar == ARG_FOUND || EnvHasValue("MOZ_NO_REMOTE")) {
+    mDisableRemoteClient = true;
+    mDisableRemoteServer = true;
+    gRestartWithoutRemote = true;
+    // We don't want to propagate MOZ_NO_REMOTE to potential child
+    // process.
+    SaveToEnv("MOZ_NO_REMOTE=");
+  }
+
+  ar = CheckArg("new-instance");
+  if (ar == ARG_FOUND || EnvHasValue("MOZ_NEW_INSTANCE")) {
+    mDisableRemoteClient = true;
+  }
+#else
+  // These arguments do nothing in platforms with no remoting support but we
+  // should remove them from the command line anyway.
+  CheckArg("no-remote");
+  CheckArg("new-instance");
+#endif
+
+  ar = CheckArg("offline");
+  if (ar || EnvHasValue("XRE_START_OFFLINE")) {
+    mStartOffline = true;
+  }
+
+  // On Windows, to get working console arrangements so help/version/etc
+  // print something, we need to initialize the native app support.
+  rv = NS_CreateNativeAppSupport(getter_AddRefs(mNativeApp));
+  if (NS_FAILED(rv)) return 1;
+
+  // Handle --help, --full-version and --version command line arguments.
+  // They should return quickly, so we deal with them here.
+  if (CheckArg("h") || CheckArg("help") || CheckArg("?")) {
+    DumpHelp();
+    *aExitFlag = true;
+    return 0;
+  }
+
+  if (CheckArg("v") || CheckArg("version")) {
+    DumpVersion();
+    *aExitFlag = true;
+    return 0;
+  }
+
+  if (CheckArg("full-version")) {
+    DumpFullVersion();
+    *aExitFlag = true;
+    return 0;
+  }
+
+  rv = XRE_InitCommandLine(gArgc, gArgv);
+  NS_ENSURE_SUCCESS(rv, 1);
+
+  return 0;
+}
+
+#if defined(XP_LINUX) && !defined(ANDROID)
+
+static void AnnotateLSBRelease(void*) {
+  nsCString dist, desc, release, codename;
+  if (widget::lsb::GetLSBRelease(dist, desc, release, codename)) {
+    CrashReporter::AppendAppNotesToCrashReport(desc);
+  }
+}
+
+#endif  // defined(XP_LINUX) && !defined(ANDROID)
+
+#ifdef XP_WIN
+static void ReadAheadSystemDll(const wchar_t* dllName) {
+  wchar_t dllPath[MAX_PATH];
+  if (ConstructSystem32Path(dllName, dllPath, MAX_PATH)) {
+    ReadAheadLib(dllPath);
+  }
+}
+
+static void ReadAheadPackagedDll(const wchar_t* dllName,
+                                 const wchar_t* aGREDir) {
+  wchar_t dllPath[MAX_PATH];
+  swprintf(dllPath, MAX_PATH, L"%s\\%s", aGREDir, dllName);
+  ReadAheadLib(dllPath);
+}
+
+static void PR_CALLBACK ReadAheadDlls_ThreadStart(void* arg) {
+  UniquePtr<wchar_t[]> greDir(static_cast<wchar_t*>(arg));
+
+  // In Bug 1628903, we investigated which DLLs we should prefetch in
+  // order to reduce disk I/O and improve startup on Windows machines.
+  // Our ultimate goal is to measure the impact of these improvements on
+  // retention (see Bug 1640087). Before we place this within a pref,
+  // we should ensure this feature only ships to the nightly channel
+  // and monitor results from that subset.
+  if (greDir) {
+    // Prefetch the DLLs shipped with firefox
+    ReadAheadPackagedDll(L"libegl.dll", greDir.get());
+    ReadAheadPackagedDll(L"libGLESv2.dll", greDir.get());
+    ReadAheadPackagedDll(L"nssckbi.dll", greDir.get());
+    ReadAheadPackagedDll(L"freebl3.dll", greDir.get());
+    ReadAheadPackagedDll(L"softokn3.dll", greDir.get());
+
+    // Prefetch the system DLLs
+    ReadAheadSystemDll(L"DWrite.dll");
+    ReadAheadSystemDll(L"D3DCompiler_47.dll");
+  } else {
+    // Load DataExchange.dll and twinapi.appcore.dll for
+    // nsWindow::EnableDragDrop
+    ReadAheadSystemDll(L"DataExchange.dll");
+    ReadAheadSystemDll(L"twinapi.appcore.dll");
+
+    // Load twinapi.dll for WindowsUIUtils::UpdateTabletModeState
+    ReadAheadSystemDll(L"twinapi.dll");
+
+    // Load explorerframe.dll for WinTaskbar::Initialize
+    ReadAheadSystemDll(L"ExplorerFrame.dll");
+
+    // Load WinTypes.dll for nsOSHelperAppService::GetApplicationDescription
+    ReadAheadSystemDll(L"WinTypes.dll");
+  }
+}
+#endif
+
+#if defined(MOZ_UPDATER) && !defined(MOZ_WIDGET_ANDROID)
+enum struct ShouldNotProcessUpdatesReason {
+  DevToolsLaunching,
+  NotAnUpdatingTask,
+  OtherInstanceRunning,
+};
+
+const char* ShouldNotProcessUpdatesReasonAsString(
+    ShouldNotProcessUpdatesReason aReason) {
+  switch (aReason) {
+    case ShouldNotProcessUpdatesReason::DevToolsLaunching:
+      return "DevToolsLaunching";
+    case ShouldNotProcessUpdatesReason::NotAnUpdatingTask:
+      return "NotAnUpdatingTask";
+    case ShouldNotProcessUpdatesReason::OtherInstanceRunning:
+      return "OtherInstanceRunning";
+    default:
+      MOZ_CRASH("impossible value for ShouldNotProcessUpdatesReason");
+  }
+}
+
+Maybe<ShouldNotProcessUpdatesReason> ShouldNotProcessUpdates(
+    nsXREDirProvider& aDirProvider) {
+  // Do not process updates if we're launching devtools, as evidenced by
+  // "--chrome ..." with the browser toolbox chrome document URL.
+
+  // Keep this synchronized with the value of the same name in
+  // devtools/client/framework/browser-toolbox/Launcher.sys.mjs.  Or, for bonus
+  // points, lift this value to nsIXulRuntime or similar, so that it can be
+  // accessed in both locations.  (The prefs service isn't available at this
+  // point so the simplest manner of sharing the value is not available to us.)
+  const char* BROWSER_TOOLBOX_WINDOW_URL =
+      "chrome://devtools/content/framework/browser-toolbox/window.html";
+
+  const char* chromeParam = nullptr;
+  if (ARG_FOUND == CheckArg("chrome", &chromeParam, CheckArgFlag::None)) {
+    if (!chromeParam || !strcmp(BROWSER_TOOLBOX_WINDOW_URL, chromeParam)) {
+      NS_WARNING("ShouldNotProcessUpdates(): DevToolsLaunching");
+      return Some(ShouldNotProcessUpdatesReason::DevToolsLaunching);
+    }
+  }
+
+#  ifdef MOZ_BACKGROUNDTASKS
+  // Do not process updates if we're running a background task mode and another
+  // instance is already running.  This avoids periodic maintenance updating
+  // underneath a browsing session.
+  Maybe<nsCString> backgroundTasks = BackgroundTasks::GetBackgroundTasks();
+  if (backgroundTasks.isSome()) {
+    // Only process updates for specific tasks: at this time, the
+    // `backgroundupdate` task and the test-only `shouldprocessupdates` task.
+    //
+    // Background tasks can be sparked by Firefox instances that are shutting
+    // down, which can cause races between the task startup trying to update and
+    // Firefox trying to invoke the updater.  This happened when converting
+    // `pingsender` to a background task, since it is launched to send pings at
+    // shutdown: Bug 1736373.
+    //
+    // We'd prefer to have this be a property of the task definition sibling to
+    // `backgroundTaskTimeoutSec`, but when we reach this code we're well before
+    // we can load the task JSM.
+    if (!BackgroundTasks::IsUpdatingTaskName(backgroundTasks.ref())) {
+      NS_WARNING("ShouldNotProcessUpdates(): NotAnUpdatingTask");
+      return Some(ShouldNotProcessUpdatesReason::NotAnUpdatingTask);
+    }
+
+    // At this point we have a dir provider but no XPCOM directory service.  We
+    // launch the update sync manager using that information so that it doesn't
+    // need to ask for (and fail to find) the directory service.
+    nsCOMPtr<nsIFile> anAppFile;
+    bool persistent;
+    nsresult rv = aDirProvider.GetFile(XRE_EXECUTABLE_FILE, &persistent,
+                                       getter_AddRefs(anAppFile));
+    if (NS_FAILED(rv) || !anAppFile) {
+      // Strange, but not a reason to skip processing updates.
+      return Nothing();
+    }
+
+    auto updateSyncManager = new nsUpdateSyncManager(anAppFile);
+
+    bool otherInstance = false;
+    updateSyncManager->IsOtherInstanceRunning(&otherInstance);
+    if (otherInstance) {
+      NS_WARNING("ShouldNotProcessUpdates(): OtherInstanceRunning");
+      return Some(ShouldNotProcessUpdatesReason::OtherInstanceRunning);
+    }
+  }
+#  endif
+
+  return Nothing();
+}
+#endif
+
+namespace mozilla::startup {
+Result<nsCOMPtr<nsIFile>, nsresult> GetIncompleteStartupFile(nsIFile* aProfLD) {
+  nsCOMPtr<nsIFile> crashFile;
+  MOZ_TRY(aProfLD->Clone(getter_AddRefs(crashFile)));
+  MOZ_TRY(crashFile->Append(FILE_STARTUP_INCOMPLETE));
+  return std::move(crashFile);
+}
+}  // namespace mozilla::startup
+
+// Check whether the last startup attempt resulted in a crash or hang.
+// This is distinct from the definition of a startup crash from
+// nsAppStartup::TrackStartupCrashBegin.
+bool XREMain::CheckLastStartupWasCrash() {
+  Result<nsCOMPtr<nsIFile>, nsresult> crashFile =
+      GetIncompleteStartupFile(mProfLD);
+  if (crashFile.isErr()) {
+    return true;
+  }
+
+  // Attempt to create the incomplete startup canary file. If the file already
+  // exists, this fails, and we know the last startup was a crash. If it
+  // doesn't already exist, it is created, and will be removed at the end of
+  // the startup crash detection window.
+  AutoFDClose fd;
+  Unused << crashFile.inspect()->OpenNSPRFileDesc(
+      PR_WRONLY | PR_CREATE_FILE | PR_EXCL, 0666, &fd.rwget());
+  return !fd;
+}
+
+/*
+ * XRE_mainStartup - Initializes the profile and various other services.
+ * Main() will exit early if either return value != 0 or if aExitFlag is
+ * true.
+ */
+int XREMain::XRE_mainStartup(bool* aExitFlag) {
+  nsresult rv;
+
+  if (!aExitFlag) return 1;
+  *aExitFlag = false;
+
+#ifdef XP_MACOSX
+  mozilla::MacAutoreleasePool pool;
+#endif
+
+  // Enable Telemetry IO Reporting on DEBUG, nightly and local builds,
+  // but disable it on FUZZING builds and for ANDROID.
+#ifndef FUZZING
+#  ifndef ANDROID
+#    ifdef DEBUG
+  mozilla::Telemetry::InitIOReporting(gAppData->xreDirectory);
+#    else
+  {
+    const char* releaseChannel = MOZ_STRINGIFY(MOZ_UPDATE_CHANNEL);
+    if (strcmp(releaseChannel, "nightly") == 0 ||
+        strcmp(releaseChannel, "default") == 0) {
+      mozilla::Telemetry::InitIOReporting(gAppData->xreDirectory);
+    }
+  }
+#    endif /* DEBUG */
+#  endif   /* ANDROID */
+#endif     /* FUZZING */
+
+#if defined(XP_WIN)
+  // Enable the HeapEnableTerminationOnCorruption exploit mitigation. We ignore
+  // the return code because it always returns success, although it has no
+  // effect on Windows older than XP SP3.
+  HeapSetInformation(NULL, HeapEnableTerminationOnCorruption, NULL, 0);
+#endif /* XP_WIN */
+
+#ifdef MOZ_WIDGET_GTK
+  // Stash startup token in owned memory because gtk_init will clear
+  // DESKTOP_STARTUP_ID it.
+  if (const char* v = PR_GetEnv("DESKTOP_STARTUP_ID")) {
+    mDesktopStartupID.Assign(v);
+  }
+  if (const char* v = PR_GetEnv("XDG_ACTIVATION_TOKEN")) {
+    mXDGActivationToken.Assign(v);
+  }
+#endif
+
+#if defined(XP_WIN)
+  {
+    // Save the shortcut path before lpTitle is replaced by an AUMID,
+    // such as by WinTaskbar
+    STARTUPINFOW si;
+    GetStartupInfoW(&si);
+    if (si.dwFlags & STARTF_TITLEISAPPID) {
+      NS_WARNING("AUMID was already set, shortcut may have been lost.");
+    } else if ((si.dwFlags & STARTF_TITLEISLINKNAME) && si.lpTitle) {
+      gProcessStartupShortcut.Assign(si.lpTitle);
+    }
+  }
+#endif /* XP_WIN */
+
+#if defined(MOZ_WIDGET_GTK)
+  // setup for private colormap.  Ideally we'd like to do this
+  // in nsAppShell::Create, but we need to get in before gtk
+  // has been initialized to make sure everything is running
+  // consistently.
+
+  // Set program name to the one defined in application.ini.
+  g_set_prgname(gAppData->remotingName);
+
+  // Initialize GTK here for splash.
+
+#  if defined(MOZ_WIDGET_GTK) && defined(MOZ_X11)
+  // Disable XInput2 multidevice support due to focus bugginess.
+  // See bugs 1182700, 1170342.
+  // gdk_disable_multidevice() affects Gdk X11 backend only,
+  // the multidevice support is always enabled on Wayland backend.
+  const char* useXI2 = PR_GetEnv("MOZ_USE_XINPUT2");
+  if (!useXI2 || (*useXI2 == '0')) gdk_disable_multidevice();
+#  endif
+
+  // Open the display ourselves instead of using gtk_init, so that we can
+  // close it without fear that one day gtk might clean up the display it
+  // opens.
+  if (!gtk_parse_args(&gArgc, &gArgv)) return 1;
+#endif /* MOZ_WIDGET_GTK */
+
+#ifdef FUZZING
+  if (PR_GetEnv("FUZZER")) {
+    *aExitFlag = true;
+    return mozilla::fuzzerRunner->Run(&gArgc, &gArgv);
+  }
+#endif
+
+  if (PR_GetEnv("MOZ_RUN_GTEST")) {
+    int result;
+#ifdef XP_WIN
+    UseParentConsole();
+#endif
+    // RunGTest will only be set if we're in xul-unit
+    if (mozilla::RunGTest) {
+      gIsGtest = true;
+      result = mozilla::RunGTest(&gArgc, gArgv);
+      gIsGtest = false;
+    } else {
+      result = 1;
+      printf("TEST-UNEXPECTED-FAIL | gtest | Not compiled with enable-tests\n");
+    }
+    *aExitFlag = true;
+    return result;
+  }
+
+  bool isBackgroundTaskMode = false;
+#ifdef MOZ_BACKGROUNDTASKS
+  isBackgroundTaskMode = BackgroundTasks::IsBackgroundTaskMode();
+#endif
+
+#ifdef MOZ_HAS_REMOTE
+  if (gfxPlatform::IsHeadless()) {
+    mDisableRemoteClient = true;
+    mDisableRemoteServer = true;
+  }
+#endif
+
+#ifdef MOZ_X11
+  // Init X11 in thread-safe mode. Must be called prior to the first call to
+  // XOpenDisplay (called inside gdk_display_open). This is a requirement for
+  // off main tread compositing.
+  if (!isBackgroundTaskMode && !gfxPlatform::IsHeadless()) {
+    XInitThreads();
+  }
+#endif
+#if defined(MOZ_WIDGET_GTK)
+  if (!isBackgroundTaskMode && !gfxPlatform::IsHeadless()) {
+    const char* display_name = nullptr;
+    bool saveDisplayArg = false;
+
+    // display_name is owned by gdk.
+    display_name = gdk_get_display_arg_name();
+    // if --display argument is given make sure it's
+    // also passed to ContentChild::Init() by MOZ_GDK_DISPLAY.
+    if (display_name) {
+      SaveWordToEnv("MOZ_GDK_DISPLAY", nsDependentCString(display_name));
+      saveDisplayArg = true;
+    }
+
+    bool waylandEnabled = IsWaylandEnabled();
+    // On Wayland disabled builds read X11 DISPLAY env exclusively
+    // and don't care about different displays.
+    if (!waylandEnabled && !display_name) {
+      display_name = PR_GetEnv("DISPLAY");
+      if (!display_name) {
+        PR_fprintf(PR_STDERR,
+                   "Error: no DISPLAY environment variable specified\n");
+        return 1;
+      }
+    }
+
+    if (display_name) {
+      GdkDisplay* disp = gdk_display_open(display_name);
+      if (!disp) {
+        PR_fprintf(PR_STDERR, "Error: cannot open display: %s\n", display_name);
+        return 1;
+      }
+      if (saveDisplayArg) {
+        if (GdkIsX11Display(disp)) {
+          SaveWordToEnv("DISPLAY", nsDependentCString(display_name));
+        }
+#  ifdef MOZ_WAYLAND
+        else if (GdkIsWaylandDisplay(disp)) {
+          SaveWordToEnv("WAYLAND_DISPLAY", nsDependentCString(display_name));
+        }
+#  endif
+      }
+    }
+#  ifdef MOZ_WIDGET_GTK
+    else {
+      gdk_display_manager_open_display(gdk_display_manager_get(), nullptr);
+    }
+#  endif
+  }
+#endif
+#if defined(MOZ_HAS_REMOTE)
+  // handle --remote now that xpcom is fired up
+  mRemoteService = new nsRemoteService(gAppData->remotingName);
+  if (mRemoteService && !mDisableRemoteServer) {
+    mRemoteService->LockStartup();
+    gRemoteService = mRemoteService;
+  }
+#endif
+#if defined(MOZ_WIDGET_GTK)
+  g_set_application_name(mAppData->name);
+
+#endif /* defined(MOZ_WIDGET_GTK) */
+#ifdef MOZ_X11
+  // Do this after initializing GDK, or GDK will install its own handler.
+  XRE_InstallX11ErrorHandler();
+#endif
+
+  // Call the code to install our handler
+#ifdef MOZ_JPROF
+  setupProfilingStuff();
+#endif
+
+  bool canRun = false;
+  rv = mNativeApp->Start(&canRun);
+  if (NS_FAILED(rv) || !canRun) {
+    return 1;
+  }
+
+#ifdef MOZ_WIDGET_GTK
+  // startup token might be cleared now, we recover it in case we need a
+  // restart.
+  if (!mDesktopStartupID.IsEmpty()) {
+    // Leak it with extreme prejudice!
+    PR_SetEnv(ToNewCString("DESKTOP_STARTUP_ID="_ns + mDesktopStartupID));
+  }
+
+  if (!mXDGActivationToken.IsEmpty()) {
+    // Leak it with extreme prejudice!
+    PR_SetEnv(ToNewCString("XDG_ACTIVATION_TOKEN="_ns + mXDGActivationToken));
+  }
+#endif
+
+  // Support exiting early for testing startup sequence. Bug 1360493
+  if (CheckArg("test-launch-without-hang")) {
+    *aExitFlag = true;
+    return 0;
+  }
+
+  mProfileSvc = NS_GetToolkitProfileService();
+  if (!mProfileSvc) {
+    // We failed to choose or create profile - notify user and quit
+    ProfileMissingDialog(mNativeApp);
+    return 1;
+  }
+
+  bool wasDefaultSelection;
+  nsCOMPtr<nsIToolkitProfile> profile;
+  rv = SelectProfile(mProfileSvc, mNativeApp, getter_AddRefs(mProfD),
+                     getter_AddRefs(mProfLD), getter_AddRefs(profile),
+                     &wasDefaultSelection);
+  if (rv == NS_ERROR_LAUNCHED_CHILD_PROCESS || rv == NS_ERROR_ABORT) {
+    *aExitFlag = true;
+    return 0;
+  }
+
+  if (NS_FAILED(rv)) {
+    // We failed to choose or create profile - notify user and quit
+    ProfileMissingDialog(mNativeApp);
+    return 1;
+  }
+
+#if defined(MOZ_HAS_REMOTE)
+  if (mRemoteService) {
+    // We want a unique profile name to identify the remote instance.
+    nsCString profileName;
+    if (profile) {
+      rv = profile->GetName(profileName);
+    }
+    if (!profile || NS_FAILED(rv) || profileName.IsEmpty()) {
+      // Couldn't get a name from the profile. Use the directory name?
+      nsString leafName;
+      rv = mProfD->GetLeafName(leafName);
+      if (NS_SUCCEEDED(rv)) {
+        CopyUTF16toUTF8(leafName, profileName);
+      }
+    }
+
+    mRemoteService->SetProfile(profileName);
+
+    if (!mDisableRemoteClient) {
+      // Try to remote the entire command line. If this fails, start up
+      // normally.
+#  ifdef MOZ_WIDGET_GTK
+      const auto& startupToken =
+          GdkIsWaylandDisplay() ? mXDGActivationToken : mDesktopStartupID;
+#  else
+      const nsCString startupToken;
+#  endif
+      RemoteResult rr = mRemoteService->StartClient(
+          startupToken.IsEmpty() ? nullptr : startupToken.get());
+      if (rr == REMOTE_FOUND) {
+        *aExitFlag = true;
+        mRemoteService->UnlockStartup();
+        return 0;
+      }
+      if (rr == REMOTE_ARG_BAD) {
+        mRemoteService->UnlockStartup();
+        return 1;
+      }
+    }
+  }
+#endif
+
+#if defined(MOZ_UPDATER) && !defined(MOZ_WIDGET_ANDROID)
+  Maybe<ShouldNotProcessUpdatesReason> shouldNotProcessUpdatesReason =
+      ShouldNotProcessUpdates(mDirProvider);
+  if (shouldNotProcessUpdatesReason.isNothing()) {
+    // Check for and process any available updates
+    nsCOMPtr<nsIFile> updRoot;
+    bool persistent;
+    rv = mDirProvider.GetFile(XRE_UPDATE_ROOT_DIR, &persistent,
+                              getter_AddRefs(updRoot));
+    // XRE_UPDATE_ROOT_DIR may fail. Fallback to appDir if failed
+    if (NS_FAILED(rv)) {
+      updRoot = mDirProvider.GetAppDir();
+    }
+
+    // If the MOZ_TEST_PROCESS_UPDATES environment variable already exists, then
+    // we are being called from the callback application.
+    if (EnvHasValue("MOZ_TEST_PROCESS_UPDATES")) {
+      // If the caller has asked us to log our arguments, do so.  This is used
+      // to make sure that the maintenance service successfully launches the
+      // callback application.
+      const char* logFile = nullptr;
+      if (ARG_FOUND == CheckArg("dump-args", &logFile)) {
+        FILE* logFP = fopen(logFile, "wb");
+        if (logFP) {
+          for (int i = 1; i < gRestartArgc; ++i) {
+            fprintf(logFP, "%s\n", gRestartArgv[i]);
+          }
+          fclose(logFP);
+        }
+      }
+      *aExitFlag = true;
+      return 0;
+    }
+
+    // Support for processing an update and exiting. The
+    // MOZ_TEST_PROCESS_UPDATES environment variable will be part of the
+    // updater's environment and the application that is relaunched by the
+    // updater. When the application is relaunched by the updater it will be
+    // removed below and the application will exit.
+    if (CheckArg("test-process-updates")) {
+      SaveToEnv("MOZ_TEST_PROCESS_UPDATES=1");
+    }
+    nsCOMPtr<nsIFile> exeFile, exeDir;
+    rv = mDirProvider.GetFile(XRE_EXECUTABLE_FILE, &persistent,
+                              getter_AddRefs(exeFile));
+    NS_ENSURE_SUCCESS(rv, 1);
+    rv = exeFile->GetParent(getter_AddRefs(exeDir));
+    NS_ENSURE_SUCCESS(rv, 1);
+    ProcessUpdates(mDirProvider.GetGREDir(), exeDir, updRoot, gRestartArgc,
+                   gRestartArgv, mAppData->version);
+    if (EnvHasValue("MOZ_TEST_PROCESS_UPDATES")) {
+      SaveToEnv("MOZ_TEST_PROCESS_UPDATES=");
+      *aExitFlag = true;
+      return 0;
+    }
+  } else {
+    if (CheckArg("test-process-updates") ||
+        EnvHasValue("MOZ_TEST_PROCESS_UPDATES")) {
+      // Support for testing *not* processing an update.  The launched process
+      // can witness this environment variable and conclude that its runtime
+      // environment resulted in not processing updates.
+
+      SaveToEnv(nsPrintfCString(
+                    "MOZ_TEST_PROCESS_UPDATES=ShouldNotProcessUpdates(): %s",
+                    ShouldNotProcessUpdatesReasonAsString(
+                        shouldNotProcessUpdatesReason.value()))
+                    .get());
+    }
+  }
+#endif
+
+  // We now know there is no existing instance using the selected profile. If
+  // the profile wasn't selected by specific command line arguments and the
+  // user has chosen to show the profile manager on startup then do that.
+  if (wasDefaultSelection) {
+    bool useSelectedProfile;
+    rv = mProfileSvc->GetStartWithLastProfile(&useSelectedProfile);
+    NS_ENSURE_SUCCESS(rv, 1);
+
+    if (!useSelectedProfile) {
+      rv = ShowProfileManager(mProfileSvc, mNativeApp);
+      if (rv == NS_ERROR_LAUNCHED_CHILD_PROCESS || rv == NS_ERROR_ABORT) {
+        *aExitFlag = true;
+        return 0;
+      }
+      if (NS_FAILED(rv)) {
+        return 1;
+      }
+    }
+  }
+
+  // We always want to lock the profile even if we're actually going to reset
+  // it later.
+  rv = LockProfile(mNativeApp, mProfD, mProfLD, profile,
+                   getter_AddRefs(mProfileLock));
+  if (rv == NS_ERROR_LAUNCHED_CHILD_PROCESS || rv == NS_ERROR_ABORT) {
+    *aExitFlag = true;
+    return 0;
+  } else if (NS_FAILED(rv)) {
+    return 1;
+  }
+
+  if (gDoProfileReset) {
+    if (EnvHasValue("MOZ_RESET_PROFILE_RESTART")) {
+      SaveToEnv("MOZ_RESET_PROFILE_RESTART=");
+      // We only want to restore the previous session if the profile refresh was
+      // triggered by user. And if it was a user-triggered profile refresh
+      // through, say, the safeMode dialog or the troubleshooting page, the
+      // MOZ_RESET_PROFILE_RESTART env variable would be set. Hence we set
+      // MOZ_RESET_PROFILE_MIGRATE_SESSION here so that Firefox profile migrator
+      // would migrate old session data later.
+      SaveToEnv("MOZ_RESET_PROFILE_MIGRATE_SESSION=1");
+    }
+    // Unlock the source profile.
+    mProfileLock->Unlock();
+
+    // If we're resetting a profile, create a new one and use it to startup.
+    gResetOldProfile = profile;
+    rv = mProfileSvc->CreateResetProfile(getter_AddRefs(profile));
+    if (NS_SUCCEEDED(rv)) {
+      rv = profile->GetRootDir(getter_AddRefs(mProfD));
+      NS_ENSURE_SUCCESS(rv, 1);
+      SaveFileToEnv("XRE_PROFILE_PATH", mProfD);
+
+      rv = profile->GetLocalDir(getter_AddRefs(mProfLD));
+      NS_ENSURE_SUCCESS(rv, 1);
+      SaveFileToEnv("XRE_PROFILE_LOCAL_PATH", mProfLD);
+
+      // Lock the new profile
+      rv = LockProfile(mNativeApp, mProfD, mProfLD, profile,
+                       getter_AddRefs(mProfileLock));
+      if (rv == NS_ERROR_LAUNCHED_CHILD_PROCESS || rv == NS_ERROR_ABORT) {
+        *aExitFlag = true;
+        return 0;
+      } else if (NS_FAILED(rv)) {
+        return 1;
+      }
+    } else {
+      NS_WARNING("Profile reset failed.");
+      return 1;
+    }
+  }
+
+  gProfileLock = mProfileLock;
+
+  nsAutoCString version;
+  BuildVersion(version);
+
+#ifdef TARGET_OS_ABI
+  constexpr auto osABI = nsLiteralCString{TARGET_OS_ABI};
+#else
+  // No TARGET_XPCOM_ABI, but at least the OS is known
+  constexpr auto osABI = nsLiteralCString{OS_TARGET "_UNKNOWN"};
+#endif
+
+  // Check for version compatibility with the last version of the app this
+  // profile was started with.  The format of the version stamp is defined
+  // by the BuildVersion function.
+  // Also check to see if something has happened to invalidate our
+  // fastload caches, like an app upgrade.
+
+  // If we see .purgecaches, that means someone did a make.
+  // Re-register components to catch potential changes.
+  nsCOMPtr<nsIFile> flagFile;
+  if (mAppData->directory) {
+    Unused << mAppData->directory->Clone(getter_AddRefs(flagFile));
+  }
+  if (flagFile) {
+    flagFile->AppendNative(FILE_INVALIDATE_CACHES);
+  }
+
+  bool cachesOK;
+  bool isDowngrade;
+  nsCString lastVersion;
+  bool versionOK = CheckCompatibility(
+      mProfD, version, osABI, mDirProvider.GetGREDir(), mAppData->directory,
+      flagFile, &cachesOK, &isDowngrade, lastVersion);
+
+  MOZ_RELEASE_ASSERT(!cachesOK || lastVersion.Equals(version),
+                     "Caches cannot be good if the version has changed.");
+
+#ifdef MOZ_BLOCK_PROFILE_DOWNGRADE
+  // The argument check must come first so the argument is always removed from
+  // the command line regardless of whether this is a downgrade or not.
+  if (!CheckArg("allow-downgrade") && isDowngrade &&
+      !EnvHasValue("MOZ_ALLOW_DOWNGRADE")) {
+    rv = CheckDowngrade(mProfD, mNativeApp, mProfileSvc, lastVersion);
+    if (rv == NS_ERROR_LAUNCHED_CHILD_PROCESS || rv == NS_ERROR_ABORT) {
+      *aExitFlag = true;
+      return 0;
+    }
+  }
+#endif
+
+  rv = mDirProvider.SetProfile(mProfD, mProfLD);
+  NS_ENSURE_SUCCESS(rv, 1);
+
+  //////////////////////// NOW WE HAVE A PROFILE ////////////////////////
+
+  mozilla::Telemetry::SetProfileDir(mProfD);
+
+  if (mAppData->flags & NS_XRE_ENABLE_CRASH_REPORTER) {
+    MakeOrSetMinidumpPath(mProfD);
+  }
+
+  CrashReporter::SetProfileDirectory(mProfD);
+
+#ifdef MOZ_ASAN_REPORTER
+  // In ASan reporter builds, we need to set ASan's log_path as early as
+  // possible, so it dumps its errors into files there instead of using
+  // the default stderr location. Since this is crucial for ASan reporter
+  // to work at all (and we don't want people to use a non-functional
+  // ASan reporter build), all failures while setting log_path are fatal.
+  setASanReporterPath(mProfD);
+
+  // Export to env for child processes
+  SaveFileToEnv("ASAN_REPORTER_PATH", mProfD);
+#endif
+
+  bool lastStartupWasCrash = CheckLastStartupWasCrash();
+
+  CrashReporter::AnnotateCrashReport(
+      CrashReporter::Annotation::LastStartupWasCrash, lastStartupWasCrash);
+
+  if (CheckArg("purgecaches") || PR_GetEnv("MOZ_PURGE_CACHES") ||
+      lastStartupWasCrash || gSafeMode) {
+    cachesOK = false;
+  }
+
+  CrashReporter::AnnotateCrashReport(
+      CrashReporter::Annotation::StartupCacheValid, cachesOK && versionOK);
+
+  // Every time a profile is loaded by a build with a different version,
+  // it updates the compatibility.ini file saying what version last wrote
+  // the fastload caches.  On subsequent launches if the version matches,
+  // there is no need for re-registration.  If the user loads the same
+  // profile in different builds the component registry must be
+  // re-generated to prevent mysterious component loading failures.
+  //
+  bool startupCacheValid = true;
+
+  if (!cachesOK || !versionOK) {
+    QuotaManager::InvalidateQuotaCache();
+
+    startupCacheValid = RemoveComponentRegistries(mProfD, mProfLD, false);
+
+    // Rewrite compatibility.ini to match the current build. The next run
+    // should attempt to invalidate the caches if either this run is safe mode
+    // or the attempt to invalidate the caches this time failed.
+    WriteVersion(mProfD, version, osABI, mDirProvider.GetGREDir(),
+                 mAppData->directory, gSafeMode || !startupCacheValid);
+  }
+
+  if (!startupCacheValid) StartupCache::IgnoreDiskCache();
+
+  if (flagFile) {
+    flagFile->Remove(true);
+  }
+
+  // Flush any pending page load events.
+  mozilla::glean_pings::Pageload.Submit("startup"_ns);
+
+  if (!isBackgroundTaskMode) {
+#ifdef USE_GLX_TEST
+    GfxInfo::FireGLXTestProcess();
+#endif
+#ifdef MOZ_WAYLAND
+    // Make sure we have wayland connection for main thread.
+    // It's used as template to create display connections
+    // for different threads.
+    if (IsWaylandEnabled()) {
+      MOZ_UNUSED(WaylandDisplayGet());
+    }
+#endif
+  }
+
+  return 0;
+}
+
+#if defined(MOZ_SANDBOX)
+void AddSandboxAnnotations() {
+  {
+    // Include the sandbox content level, regardless of platform
+    int level = GetEffectiveContentSandboxLevel();
+
+    nsAutoCString levelString;
+    levelString.AppendInt(level);
+
+    CrashReporter::AnnotateCrashReport(
+        CrashReporter::Annotation::ContentSandboxLevel, levelString);
+  }
+
+  {
+    int level = GetEffectiveGpuSandboxLevel();
+
+    nsAutoCString levelString;
+    levelString.AppendInt(level);
+
+    CrashReporter::AnnotateCrashReport(
+        CrashReporter::Annotation::GpuSandboxLevel, levelString);
+  }
+
+  // Include whether or not this instance is capable of content sandboxing
+  bool sandboxCapable = false;
+
+#  if defined(XP_WIN)
+  // All supported Windows versions support some level of content sandboxing
+  sandboxCapable = true;
+#  elif defined(XP_MACOSX)
+  // All supported OS X versions are capable
+  sandboxCapable = true;
+#  elif defined(XP_LINUX)
+  sandboxCapable = SandboxInfo::Get().CanSandboxContent();
+#  elif defined(__OpenBSD__)
+  sandboxCapable = true;
+  StartOpenBSDSandbox(GeckoProcessType_Default);
+#  endif
+
+  CrashReporter::AnnotateCrashReport(
+      CrashReporter::Annotation::ContentSandboxCapable, sandboxCapable);
+}
+#endif /* MOZ_SANDBOX */
+
+/*
+ * XRE_mainRun - Command line startup, profile migration, and
+ * the calling of appStartup->Run().
+ */
+nsresult XREMain::XRE_mainRun() {
+  nsresult rv = NS_OK;
+  NS_ASSERTION(mScopedXPCOM, "Scoped xpcom not initialized.");
+
+#if defined(XP_WIN)
+  RefPtr<mozilla::DllServices> dllServices(mozilla::DllServices::Get());
+  dllServices->StartUntrustedModulesProcessor(false);
+  auto dllServicesDisable =
+      MakeScopeExit([&dllServices]() { dllServices->DisableFull(); });
+
+  mozilla::mscom::InitProfilerMarkers();
+#endif  // defined(XP_WIN)
+
+  // We need the appStartup pointer to span multiple scopes, so we declare
+  // it here.
+  nsCOMPtr<nsIAppStartup> appStartup;
+  // Ditto with the command line.
+  nsCOMPtr<nsICommandLineRunner> cmdLine;
+
+  {
+#ifdef XP_MACOSX
+    // In this scope, create an autorelease pool that will leave scope with
+    // it just before entering our event loop.
+    mozilla::MacAutoreleasePool pool;
+#endif
+
+    rv = mScopedXPCOM->SetWindowCreator(mNativeApp);
+    NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);
+
+    // tell the crash reporter to also send the release channel
+    nsCOMPtr<nsIPrefService> prefs =
+        do_GetService("@mozilla.org/preferences-service;1", &rv);
+    if (NS_SUCCEEDED(rv)) {
+      nsCOMPtr<nsIPrefBranch> defaultPrefBranch;
+      rv = prefs->GetDefaultBranch(nullptr, getter_AddRefs(defaultPrefBranch));
+
+      if (NS_SUCCEEDED(rv)) {
+        nsAutoCString sval;
+        rv = defaultPrefBranch->GetCharPref("app.update.channel", sval);
+        if (NS_SUCCEEDED(rv)) {
+          CrashReporter::AnnotateCrashReport(
+              CrashReporter::Annotation::ReleaseChannel, sval);
+        }
+      }
+    }
+    // Needs to be set after xpcom initialization.
+    bool includeContextHeap = Preferences::GetBool(
+        "toolkit.crashreporter.include_context_heap", false);
+    CrashReporter::SetIncludeContextHeap(includeContextHeap);
+
+#if defined(XP_LINUX) && !defined(ANDROID)
+    PR_CreateThread(PR_USER_THREAD, AnnotateLSBRelease, 0, PR_PRIORITY_LOW,
+                    PR_GLOBAL_THREAD, PR_UNJOINABLE_THREAD, 0);
+#endif
+
+    if (mStartOffline) {
+      nsCOMPtr<nsIIOService> io(
+          do_GetService("@mozilla.org/network/io-service;1"));
+      NS_ENSURE_TRUE(io, NS_ERROR_FAILURE);
+      io->SetManageOfflineStatus(false);
+      io->SetOffline(true);
+    }
+
+#ifdef XP_WIN
+    mozilla::DllPrefetchExperimentRegistryInfo prefetchRegInfo;
+    mozilla::AlteredDllPrefetchMode dllPrefetchMode =
+        prefetchRegInfo.GetAlteredDllPrefetchMode();
+
+    if (!PR_GetEnv("XRE_NO_DLL_READAHEAD") &&
+        dllPrefetchMode != mozilla::AlteredDllPrefetchMode::NoPrefetch) {
+      nsCOMPtr<nsIFile> greDir = mDirProvider.GetGREDir();
+      nsAutoString path;
+      rv = greDir->GetPath(path);
+      if (NS_SUCCEEDED(rv)) {
+        PRThread* readAheadThread;
+        wchar_t* pathRaw;
+
+        // We use the presence of a path argument inside the thread to determine
+        // which list of Dlls to use. The old list does not need access to the
+        // GRE dir, so the path argument is set to a null pointer.
+        if (dllPrefetchMode ==
+            mozilla::AlteredDllPrefetchMode::OptimizedPrefetch) {
+          pathRaw = new wchar_t[MAX_PATH];
+          wcscpy_s(pathRaw, MAX_PATH, path.get());
+        } else {
+          pathRaw = nullptr;
+        }
+        readAheadThread = PR_CreateThread(
+            PR_USER_THREAD, ReadAheadDlls_ThreadStart, (void*)pathRaw,
+            PR_PRIORITY_NORMAL, PR_GLOBAL_THREAD, PR_UNJOINABLE_THREAD, 0);
+        if (readAheadThread == NULL) {
+          delete[] pathRaw;
+        }
+      }
+    }
+#endif
+
+    if (gDoMigration) {
+      nsCOMPtr<nsIFile> file;
+      mDirProvider.GetAppDir()->Clone(getter_AddRefs(file));
+      file->AppendNative("override.ini"_ns);
+      nsINIParser parser;
+      nsresult rv = parser.Init(file);
+      // if override.ini doesn't exist, also check for distribution.ini
+      if (NS_FAILED(rv)) {
+        bool persistent;
+        mDirProvider.GetFile(XRE_APP_DISTRIBUTION_DIR, &persistent,
+                             getter_AddRefs(file));
+        file->AppendNative("distribution.ini"_ns);
+        rv = parser.Init(file);
+      }
+      if (NS_SUCCEEDED(rv)) {
+        nsAutoCString buf;
+        rv = parser.GetString("XRE", "EnableProfileMigrator", buf);
+        if (NS_SUCCEEDED(rv)) {
+          if (buf[0] == '0' || buf[0] == 'f' || buf[0] == 'F') {
+            gDoMigration = false;
+          }
+        }
+      }
+    }
+
+    // We'd like to initialize the JSContext *after* reading the user prefs.
+    // Unfortunately that's not possible if we have to do profile migration
+    // because that requires us to execute JS before reading user prefs.
+    // Restarting the browser after profile migration would fix this. See
+    // bug 1592523.
+    bool initializedJSContext = false;
+
+    {
+      // Profile Migration
+      if (mAppData->flags & NS_XRE_ENABLE_PROFILE_MIGRATOR && gDoMigration) {
+        gDoMigration = false;
+
+        xpc::InitializeJSContext();
+        initializedJSContext = true;
+
+        nsCOMPtr<nsIProfileMigrator> pm(
+            do_CreateInstance(NS_PROFILEMIGRATOR_CONTRACTID));
+        if (pm) {
+          nsAutoCString aKey;
+          nsAutoCString aName;
+          if (gDoProfileReset) {
+            // Automatically migrate from the current application if we just
+            // reset the profile.
+            aKey = MOZ_APP_NAME;
+            gResetOldProfile->GetName(aName);
+          }
+          pm->Migrate(&mDirProvider, aKey, aName);
+        }
+      }
+
+      if (gDoProfileReset) {
+        if (!initializedJSContext) {
+          xpc::InitializeJSContext();
+          initializedJSContext = true;
+        }
+
+        nsresult backupCreated =
+            ProfileResetCleanup(mProfileSvc, gResetOldProfile);
+        if (NS_FAILED(backupCreated)) {
+          NS_WARNING("Could not cleanup the profile that was reset");
+        }
+      }
+    }
+
+    // Initialize user preferences before notifying startup observers so they're
+    // ready in time for early consumers, such as the component loader.
+    mDirProvider.InitializeUserPrefs();
+
+    // Now that all (user) prefs have been loaded we can initialize the main
+    // thread's JSContext.
+    if (!initializedJSContext) {
+      xpc::InitializeJSContext();
+    }
+
+    // Finally, now that JS has been initialized, we can finish pref loading.
+    // This needs to happen after JS and XPConnect initialization because
+    // AutoConfig files require JS execution. Note that this means AutoConfig
+    // files can't override JS engine start-up prefs.
+    mDirProvider.FinishInitializingUserPrefs();
+
+#if defined(MOZ_SANDBOX) && defined(XP_WIN)
+    // Now that we have preferences and the directory provider, we can
+    // finish initializing SandboxBroker. This must happen before the GFX
+    // platform is initialized (which will launch the GPU process), which
+    // occurs when the "app-startup" category is started up below
+    //
+    // After this completes, we are ready to launch sandboxed processes
+    mozilla::SandboxBroker::GeckoDependentInitialize();
+#endif
+
+    nsCOMPtr<nsIFile> workingDir;
+    rv = NS_GetSpecialDirectory(NS_OS_CURRENT_WORKING_DIR,
+                                getter_AddRefs(workingDir));
+    if (NS_FAILED(rv)) {
+      // No working dir? This can happen if it gets deleted before we start.
+      workingDir = nullptr;
+    }
+
+    cmdLine = new nsCommandLine();
+
+    rv = cmdLine->Init(gArgc, gArgv, workingDir,
+                       nsICommandLine::STATE_INITIAL_LAUNCH);
+    NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);
+
+    // "app-startup" is the name of both the category and the event
+    NS_CreateServicesFromCategory("app-startup", cmdLine, "app-startup",
+                                  nullptr);
+
+    appStartup = components::AppStartup::Service();
+    NS_ENSURE_TRUE(appStartup, NS_ERROR_FAILURE);
+
+    mDirProvider.DoStartup();
+
+#ifdef XP_WIN
+    // It needs to be called on the main thread because it has to use
+    // nsObserverService.
+    EnsureWin32kInitialized();
+#endif
+
+    // As FilePreferences need the profile directory, we must initialize right
+    // here.
+    mozilla::FilePreferences::InitDirectoriesAllowlist();
+    mozilla::FilePreferences::InitPrefs();
+
+    OverrideDefaultLocaleIfNeeded();
+
+    nsCString userAgentLocale;
+    LocaleService::GetInstance()->GetAppLocaleAsBCP47(userAgentLocale);
+    CrashReporter::AnnotateCrashReport(
+        CrashReporter::Annotation::useragent_locale, userAgentLocale);
+
+    if (!AppShutdown::IsInOrBeyond(ShutdownPhase::AppShutdownConfirmed)) {
+      /* Special-case services that need early access to the command
+          line. */
+      nsCOMPtr<nsIObserverService> obsService =
+          mozilla::services::GetObserverService();
+      if (obsService) {
+        obsService->NotifyObservers(cmdLine, "command-line-startup", nullptr);
+      }
+    }
+
+#ifdef XP_WIN
+    // Hack to sync up the various environment storages. XUL_APP_FILE is special
+    // in that it comes from a different CRT (firefox.exe's static-linked copy).
+    // Ugly details in http://bugzil.la/1175039#c27
+    char appFile[MAX_PATH];
+    if (GetEnvironmentVariableA("XUL_APP_FILE", appFile, sizeof(appFile))) {
+      SmprintfPointer saved = mozilla::Smprintf("XUL_APP_FILE=%s", appFile);
+      // We intentionally leak the string here since it is required by
+      // PR_SetEnv.
+      PR_SetEnv(saved.release());
+    }
+#endif
+
+    mozilla::AppShutdown::SaveEnvVarsForPotentialRestart();
+
+    // clear out any environment variables which may have been set
+    // during the relaunch process now that we know we won't be relaunching.
+    SaveToEnv("XRE_PROFILE_PATH=");
+    SaveToEnv("XRE_PROFILE_LOCAL_PATH=");
+    SaveToEnv("XRE_START_OFFLINE=");
+    SaveToEnv("XUL_APP_FILE=");
+    SaveToEnv("XRE_BINARY_PATH=");
+    SaveToEnv("XRE_RESTARTED_BY_PROFILE_MANAGER=");
+
+    if (!AppShutdown::IsInOrBeyond(ShutdownPhase::AppShutdownConfirmed)) {
+#ifdef XP_MACOSX
+      bool lazyHiddenWindow = false;
+#else
+      bool lazyHiddenWindow =
+          Preferences::GetBool("toolkit.lazyHiddenWindow", false);
+#endif
+
+#ifdef MOZ_BACKGROUNDTASKS
+      if (BackgroundTasks::IsBackgroundTaskMode()) {
+        // Background tasks aren't going to load a chrome XUL document.
+        lazyHiddenWindow = true;
+      }
+#endif
+
+      if (!lazyHiddenWindow) {
+        rv = appStartup->CreateHiddenWindow();
+        NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);
+      }
+
+#ifdef XP_WIN
+      Preferences::RegisterCallbackAndCall(
+          RegisterApplicationRestartChanged,
+          PREF_WIN_REGISTER_APPLICATION_RESTART);
+      SetupAlteredPrefetchPref();
+      SetupSkeletonUIPrefs();
+#  if defined(MOZ_LAUNCHER_PROCESS)
+      SetupLauncherProcessPref();
+#  endif  // defined(MOZ_LAUNCHER_PROCESS)
+#  if defined(MOZ_DEFAULT_BROWSER_AGENT)
+#    if defined(MOZ_BACKGROUNDTASKS)
+      // The backgroundtask profile is not a browsing profile, let alone the new
+      // default profile, so don't mirror its properties into the registry.
+      if (!BackgroundTasks::IsBackgroundTaskMode())
+#    endif  // defined(MOZ_BACKGROUNDTASKS)
+      {
+        Preferences::RegisterCallbackAndCall(
+            &OnDefaultAgentTelemetryPrefChanged,
+            kPrefHealthReportUploadEnabled);
+        Preferences::RegisterCallbackAndCall(
+            &OnDefaultAgentTelemetryPrefChanged, kPrefDefaultAgentEnabled);
+
+        Preferences::RegisterCallbackAndCall(
+            &OnDefaultAgentRemoteSettingsPrefChanged,
+            kPrefServicesSettingsServer);
+        Preferences::RegisterCallbackAndCall(
+            &OnDefaultAgentRemoteSettingsPrefChanged,
+            kPrefSecurityContentSignatureRootHash);
+
+        Preferences::RegisterCallbackAndCall(
+            &OnSetDefaultBrowserUserChoicePrefChanged,
+            kPrefSetDefaultBrowserUserChoicePref);
+
+        SetDefaultAgentLastRunTime();
+      }
+#  endif  // defined(MOZ_DEFAULT_BROWSER_AGENT)
+#endif
+
+#if defined(MOZ_WIDGET_GTK)
+      // Clear the environment variables so they won't be inherited by child
+      // processes and confuse things.
+      for (const auto& name : kStartupTokenNames) {
+        g_unsetenv(name.get());
+      }
+#endif
+
+#ifdef XP_MACOSX
+      // we re-initialize the command-line service and do appleevents munging
+      // after we are sure that we're not restarting
+      cmdLine = new nsCommandLine();
+
+      char** tempArgv = static_cast<char**>(malloc(gArgc * sizeof(char*)));
+      for (int i = 0; i < gArgc; i++) {
+        tempArgv[i] = strdup(gArgv[i]);
+      }
+      CommandLineServiceMac::SetupMacCommandLine(gArgc, tempArgv, false);
+      rv = cmdLine->Init(gArgc, tempArgv, workingDir,
+                         nsICommandLine::STATE_INITIAL_LAUNCH);
+      free(tempArgv);
+      NS_ENSURE_SUCCESS(rv, NS_ERROR_FAILURE);
+
+#  ifdef MOZILLA_OFFICIAL
+      // Check if we're running from a DMG or an app translocated location and
+      // allow the user to install to the Applications directory.
+      if (MacRunFromDmgUtils::MaybeInstallAndRelaunch()) {
+        bool userAllowedQuit = true;
+        appStartup->Quit(nsIAppStartup::eForceQuit, 0, &userAllowedQuit);
+      }
+#  endif
+#endif
+
+      nsCOMPtr<nsIObserverService> obsService =
+          mozilla::services::GetObserverService();
+      if (obsService)
+        obsService->NotifyObservers(nullptr, "final-ui-startup", nullptr);
+
+      (void)appStartup->DoneStartingUp();
+
+      CrashReporter::AnnotateCrashReport(
+          CrashReporter::Annotation::StartupCrash, false);
+
+      AppShutdown::IsInOrBeyond(ShutdownPhase::AppShutdownConfirmed);
+    }
+
+    if (!AppShutdown::IsInOrBeyond(ShutdownPhase::AppShutdownConfirmed)) {
+      rv = cmdLine->Run();
+      NS_ENSURE_SUCCESS_LOG(rv, NS_ERROR_FAILURE);
+    }
+
+    if (!AppShutdown::IsInOrBeyond(ShutdownPhase::AppShutdownConfirmed)) {
+#if defined(MOZ_HAS_REMOTE)
+      // if we have X remote support, start listening for requests on the
+      // proxy window.
+      if (mRemoteService && !mDisableRemoteServer) {
+        mRemoteService->StartupServer();
+        mRemoteService->UnlockStartup();
+        gRemoteService = nullptr;
+      }
+#endif /* MOZ_WIDGET_GTK */
+
+      mNativeApp->Enable();
+    }
+
+#ifdef MOZ_INSTRUMENT_EVENT_LOOP
+    if (PR_GetEnv("MOZ_INSTRUMENT_EVENT_LOOP")) {
+      bool logToConsole = true;
+      mozilla::InitEventTracing(logToConsole);
+    }
+#endif /* MOZ_INSTRUMENT_EVENT_LOOP */
+
+    // Send Telemetry about Gecko version and buildid
+    Telemetry::ScalarSet(Telemetry::ScalarID::GECKO_VERSION,
+                         NS_ConvertASCIItoUTF16(gAppData->version));
+    Telemetry::ScalarSet(Telemetry::ScalarID::GECKO_BUILD_ID,
+                         NS_ConvertASCIItoUTF16(gAppData->buildID));
+
+#if defined(MOZ_SANDBOX) && defined(XP_LINUX)
+    // If we're on Linux, we now have information about the OS capabilities
+    // available to us.
+    SandboxInfo sandboxInfo = SandboxInfo::Get();
+    Telemetry::Accumulate(Telemetry::SANDBOX_HAS_SECCOMP_BPF,
+                          sandboxInfo.Test(SandboxInfo::kHasSeccompBPF));
+    Telemetry::Accumulate(Telemetry::SANDBOX_HAS_SECCOMP_TSYNC,
+                          sandboxInfo.Test(SandboxInfo::kHasSeccompTSync));
+    Telemetry::Accumulate(
+        Telemetry::SANDBOX_HAS_USER_NAMESPACES_PRIVILEGED,
+        sandboxInfo.Test(SandboxInfo::kHasPrivilegedUserNamespaces));
+    Telemetry::Accumulate(Telemetry::SANDBOX_HAS_USER_NAMESPACES,
+                          sandboxInfo.Test(SandboxInfo::kHasUserNamespaces));
+    Telemetry::Accumulate(Telemetry::SANDBOX_CONTENT_ENABLED,
+                          sandboxInfo.Test(SandboxInfo::kEnabledForContent));
+    Telemetry::Accumulate(Telemetry::SANDBOX_MEDIA_ENABLED,
+                          sandboxInfo.Test(SandboxInfo::kEnabledForMedia));
+    nsAutoCString flagsString;
+    flagsString.AppendInt(sandboxInfo.AsInteger());
+
+    CrashReporter::AnnotateCrashReport(
+        CrashReporter::Annotation::ContentSandboxCapabilities, flagsString);
+#endif /* MOZ_SANDBOX && XP_LINUX */
+
+#if defined(XP_WIN)
+    LauncherResult<bool> isAdminWithoutUac = IsAdminWithoutUac();
+    if (isAdminWithoutUac.isOk()) {
+      Telemetry::ScalarSet(
+          Telemetry::ScalarID::OS_ENVIRONMENT_IS_ADMIN_WITHOUT_UAC,
+          isAdminWithoutUac.unwrap());
+    }
+#endif /* XP_WIN */
+
+#if defined(MOZ_SANDBOX)
+    AddSandboxAnnotations();
+#endif /* MOZ_SANDBOX */
+
+    mProfileSvc->CompleteStartup();
+  }
+
+#ifdef MOZ_BACKGROUNDTASKS
+  if (BackgroundTasks::IsBackgroundTaskMode()) {
+    // In background task mode, we don't fire various delayed initialization
+    // notifications, which in the regular browser is how startup crash tracking
+    // is marked as finished.  Here, getting this far means we don't have a
+    // startup crash.
+    rv = appStartup->TrackStartupCrashEnd();
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // We never open a window, but don't want to exit immediately.
+    rv = appStartup->EnterLastWindowClosingSurvivalArea();
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    // Avoid some small differences in initialization order across platforms.
+    nsCOMPtr<nsIPowerManagerService> powerManagerService =
+        do_GetService(POWERMANAGERSERVICE_CONTRACTID);
+    nsCOMPtr<nsIStringBundleService> stringBundleService =
+        do_GetService(NS_STRINGBUNDLE_CONTRACTID);
+
+    rv = BackgroundTasks::RunBackgroundTask(cmdLine);
+    NS_ENSURE_SUCCESS(rv, rv);
+  }
+#endif
+
+  {
+    rv = appStartup->Run();
+    if (NS_FAILED(rv)) {
+      NS_ERROR("failed to run appstartup");
+      gLogConsoleErrors = true;
+    }
+  }
+
+  return rv;
+}
+
+#if defined(MOZ_WIDGET_ANDROID)
+static already_AddRefed<nsIFile> GreOmniPath(int argc, char** argv) {
+  nsresult rv;
+
+  const char* path = nullptr;
+  ArgResult ar = CheckArg(argc, argv, "greomni", &path, CheckArgFlag::None);
+  if (ar == ARG_BAD) {
+    PR_fprintf(PR_STDERR,
+               "Error: argument --greomni requires a path argument\n");
+    return nullptr;
+  }
+
+  if (!path) return nullptr;
+
+  nsCOMPtr<nsIFile> greOmni;
+  rv = XRE_GetFileFromPath(path, getter_AddRefs(greOmni));
+  if (NS_FAILED(rv)) {
+    PR_fprintf(PR_STDERR, "Error: argument --greomni requires a valid path\n");
+    return nullptr;
+  }
+
+  return greOmni.forget();
+}
+#endif
+
+/*
+ * XRE_main - A class based main entry point used by most platforms.
+ *            Note that on OSX, aAppData->xreDirectory will point to
+ *            .app/Contents/Resources.
+ */
+int XREMain::XRE_main(int argc, char* argv[], const BootstrapConfig& aConfig) {
+  gArgc = argc;
+  gArgv = argv;
+
+  ScopedLogging log;
+
+  mozilla::LogModule::Init(gArgc, gArgv);
+
+#ifndef XP_LINUX
+  NS_SetCurrentThreadName("MainThread");
+#endif
+
+  AUTO_BASE_PROFILER_LABEL("XREMain::XRE_main (around Gecko Profiler)", OTHER);
+  AUTO_PROFILER_INIT;
+  AUTO_PROFILER_LABEL("XREMain::XRE_main", OTHER);
+
+#ifdef XP_MACOSX
+  // We call this early because it will kick off a background-thread task
+  // to register the fonts, and we'd like it to have a chance to complete
+  // before gfxPlatform initialization actually requires it.
+  gfxPlatformMac::RegisterSupplementalFonts();
+#endif
+
+#ifdef MOZ_CODE_COVERAGE
+  CodeCoverageHandler::Init();
+#endif
+
+  nsresult rv = NS_OK;
+
+  if (aConfig.appData) {
+    mAppData = MakeUnique<XREAppData>(*aConfig.appData);
+  } else {
+    MOZ_RELEASE_ASSERT(aConfig.appDataPath);
+    nsCOMPtr<nsIFile> appini;
+    rv = XRE_GetFileFromPath(aConfig.appDataPath, getter_AddRefs(appini));
+    if (NS_FAILED(rv)) {
+      Output(true, "Error: unrecognized path: %s\n", aConfig.appDataPath);
+      return 1;
+    }
+
+    mAppData = MakeUnique<XREAppData>();
+    rv = XRE_ParseAppData(appini, *mAppData);
+    if (NS_FAILED(rv)) {
+      Output(true, "Couldn't read application.ini");
+      return 1;
+    }
+
+    appini->GetParent(getter_AddRefs(mAppData->directory));
+  }
+
+  if (!mAppData->remotingName) {
+    mAppData->remotingName = mAppData->name;
+  }
+  // used throughout this file
+  gAppData = mAppData.get();
+
+  nsCOMPtr<nsIFile> binFile;
+  rv = XRE_GetBinaryPath(getter_AddRefs(binFile));
+  NS_ENSURE_SUCCESS(rv, 1);
+
+  rv = binFile->GetPath(gAbsoluteArgv0Path);
+  NS_ENSURE_SUCCESS(rv, 1);
+
+  if (!mAppData->xreDirectory) {
+    nsCOMPtr<nsIFile> greDir;
+
+#if defined(MOZ_WIDGET_ANDROID)
+    greDir = GreOmniPath(argc, argv);
+    if (!greDir) {
+      return 2;
+    }
+#else
+    rv = binFile->GetParent(getter_AddRefs(greDir));
+    if (NS_FAILED(rv)) return 2;
+#endif
+
+#ifdef XP_MACOSX
+    nsCOMPtr<nsIFile> parent;
+    greDir->GetParent(getter_AddRefs(parent));
+    greDir = parent.forget();
+    greDir->AppendNative("Resources"_ns);
+#endif
+
+    mAppData->xreDirectory = greDir;
+  }
+
+#if defined(MOZ_WIDGET_ANDROID)
+  nsCOMPtr<nsIFile> dataDir;
+  rv = binFile->GetParent(getter_AddRefs(dataDir));
+  if (NS_FAILED(rv)) return 2;
+
+  mAppData->directory = dataDir;
+#else
+  if (aConfig.appData && aConfig.appDataPath) {
+    mAppData->xreDirectory->Clone(getter_AddRefs(mAppData->directory));
+    mAppData->directory->AppendNative(nsDependentCString(aConfig.appDataPath));
+  }
+#endif
+
+  if (!mAppData->directory) {
+    mAppData->directory = mAppData->xreDirectory;
+  }
+
+#if defined(XP_WIN)
+#  if defined(MOZ_SANDBOX)
+  mAppData->sandboxBrokerServices = aConfig.sandboxBrokerServices;
+#  endif  // defined(MOZ_SANDBOX)
+
+  {
+    DebugOnly<bool> result = WindowsBCryptInitialization();
+    MOZ_ASSERT(result);
+  }
+#endif  // defined(XP_WIN)
+
+  // Once we unset the exception handler, we lose the ability to properly
+  // detect hangs -- they show up as crashes.  We do this as late as possible.
+  // In particular, after ProcessRuntime is destroyed on Windows.
+  auto unsetExceptionHandler = MakeScopeExit([&] {
+    if (mAppData->flags & NS_XRE_ENABLE_CRASH_REPORTER)
+      return CrashReporter::UnsetExceptionHandler();
+    return NS_OK;
+  });
+
+  mozilla::IOInterposerInit ioInterposerGuard;
+
+#if defined(XP_WIN)
+  // We should have already done this when we created the skeleton UI. However,
+  // there is code in here which needs xul in order to work, like EnsureMTA. It
+  // should be setup that running it again is safe.
+  mozilla::mscom::ProcessRuntime msCOMRuntime;
+#endif
+
+  // init
+  bool exit = false;
+  int result = XRE_mainInit(&exit);
+  if (result != 0 || exit) return result;
+
+  // If we exit gracefully, remove the startup crash canary file.
+  auto cleanup = MakeScopeExit([&]() -> nsresult {
+    if (mProfLD) {
+      nsCOMPtr<nsIFile> crashFile;
+      MOZ_TRY_VAR(crashFile, GetIncompleteStartupFile(mProfLD));
+      crashFile->Remove(false);
+    }
+    return NS_OK;
+  });
+
+  // startup
+  result = XRE_mainStartup(&exit);
+  if (result != 0 || exit) return result;
+
+  // Start the real application. We use |aInitJSContext = false| because
+  // XRE_mainRun wants to initialize the JSContext after reading user prefs.
+
+  mScopedXPCOM = MakeUnique<ScopedXPCOMStartup>();
+
+  rv = mScopedXPCOM->Initialize(/* aInitJSContext = */ false);
+  NS_ENSURE_SUCCESS(rv, 1);
+
+  // run!
+  rv = XRE_mainRun();
+
+#ifdef MOZ_X11
+  XRE_CleanupX11ErrorHandler();
+#endif
+
+#ifdef MOZ_INSTRUMENT_EVENT_LOOP
+  mozilla::ShutdownEventTracing();
+#endif
+
+  gAbsoluteArgv0Path.Truncate();
+
+#if defined(MOZ_HAS_REMOTE)
+  // Shut down the remote service. We must do this before calling LaunchChild
+  // if we're restarting because otherwise the new instance will attempt to
+  // remote to this instance.
+  if (mRemoteService && !mDisableRemoteServer) {
+    mRemoteService->ShutdownServer();
+  }
+#endif /* MOZ_WIDGET_GTK */
+
+  mScopedXPCOM = nullptr;
+
+  // unlock the profile after ScopedXPCOMStartup object (xpcom)
+  // has gone out of scope.  see bug #386739 for more details
+  mProfileLock->Unlock();
+  gProfileLock = nullptr;
+
+  gLastAppVersion.Truncate();
+  gLastAppBuildID.Truncate();
+
+  mozilla::AppShutdown::MaybeDoRestart();
+
+#ifdef MOZ_WIDGET_GTK
+  // gdk_display_close also calls gdk_display_manager_set_default_display
+  // appropriately when necessary.
+  if (!gfxPlatform::IsHeadless()) {
+#  ifdef MOZ_WAYLAND
+    WaylandDisplayRelease();
+#  endif
+  }
+#endif
+
+  XRE_DeinitCommandLine();
+
+  if (NS_FAILED(rv)) {
+    return 1;
+  }
+  return mozilla::AppShutdown::GetExitCode();
+}
+
+void XRE_StopLateWriteChecks(void) { mozilla::StopLateWriteChecks(); }
+
+int XRE_main(int argc, char* argv[], const BootstrapConfig& aConfig) {
+  XREMain main;
+
+  int result = main.XRE_main(argc, argv, aConfig);
+  mozilla::RecordShutdownEndTimeStamp();
+#ifdef MOZ_BACKGROUNDTASKS
+  // This is well after the profile has been unlocked, so it's okay if this does
+  // delete this background task's temporary profile.
+  mozilla::BackgroundTasks::Shutdown();
+#endif
+  return result;
+}
+
+nsresult XRE_InitCommandLine(int aArgc, char* aArgv[]) {
+  nsresult rv = NS_OK;
+
+#if defined(OS_WIN)
+  CommandLine::Init(aArgc, aArgv);
+#else
+
+  // these leak on error, but that's OK: we'll just exit()
+  char** canonArgs = new char*[aArgc];
+
+  // get the canonical version of the binary's path
+  nsCOMPtr<nsIFile> binFile;
+  rv = XRE_GetBinaryPath(getter_AddRefs(binFile));
+  if (NS_FAILED(rv)) return NS_ERROR_FAILURE;
+
+  nsAutoCString canonBinPath;
+  rv = binFile->GetNativePath(canonBinPath);
+  if (NS_FAILED(rv)) return NS_ERROR_FAILURE;
+
+  canonArgs[0] = strdup(canonBinPath.get());
+
+  for (int i = 1; i < aArgc; ++i) {
+    if (aArgv[i]) {
+      canonArgs[i] = strdup(aArgv[i]);
+    }
+  }
+
+  NS_ASSERTION(!CommandLine::IsInitialized(), "Bad news!");
+  CommandLine::Init(aArgc, canonArgs);
+
+  for (int i = 0; i < aArgc; ++i) free(canonArgs[i]);
+  delete[] canonArgs;
+#endif
+
+#if defined(MOZ_WIDGET_ANDROID)
+  nsCOMPtr<nsIFile> greOmni =
+      gAppData ? gAppData->xreDirectory : GreOmniPath(aArgc, aArgv);
+  if (!greOmni) {
+    return NS_ERROR_FAILURE;
+  }
+  mozilla::Omnijar::Init(greOmni, greOmni);
+#endif
+
+  return rv;
+}
+
+nsresult XRE_DeinitCommandLine() {
+  nsresult rv = NS_OK;
+
+  CommandLine::Terminate();
+
+  return rv;
+}
+
+GeckoProcessType XRE_GetProcessType() { return GetGeckoProcessType(); }
+
+const char* XRE_GetProcessTypeString() {
+  return XRE_GeckoProcessTypeToString(XRE_GetProcessType());
+}
+
+bool XRE_IsE10sParentProcess() {
+#ifdef MOZ_WIDGET_ANDROID
+  return XRE_IsParentProcess() && BrowserTabsRemoteAutostart() &&
+         mozilla::jni::IsAvailable();
+#else
+  return XRE_IsParentProcess() && BrowserTabsRemoteAutostart();
+#endif
+}
+
+#define GECKO_PROCESS_TYPE(enum_value, enum_name, string_name, proc_typename, \
+                           process_bin_type, procinfo_typename,               \
+                           webidl_typename, allcaps_name)                     \
+  bool XRE_Is##proc_typename##Process() {                                     \
+    return XRE_GetProcessType() == GeckoProcessType_##enum_name;              \
+  }
+#include "mozilla/GeckoProcessTypes.h"
+#undef GECKO_PROCESS_TYPE
+
+bool XRE_UseNativeEventProcessing() {
+  switch (XRE_GetProcessType()) {
+#if defined(XP_MACOSX) || defined(XP_WIN)
+    case GeckoProcessType_RDD:
+    case GeckoProcessType_Socket:
+      return false;
+    case GeckoProcessType_Utility: {
+#  if defined(XP_WIN)
+      auto upc = mozilla::ipc::UtilityProcessChild::Get();
+      MOZ_ASSERT(upc);
+      // WindowsUtils is for Windows APIs, which typically require a Windows
+      // native event loop.
+      return upc->mSandbox == mozilla::ipc::SandboxingKind::WINDOWS_UTILS;
+#  else
+      return false;
+#  endif  // defined(XP_WIN)
+    }
+#endif  // defined(XP_MACOSX) || defined(XP_WIN)
+    case GeckoProcessType_Content:
+      return StaticPrefs::dom_ipc_useNativeEventProcessing_content();
+    default:
+      return true;
+  }
+}
+
+namespace mozilla {
+
+uint32_t GetMaxWebProcessCount() {
+  // multiOptOut is in int to allow us to run multiple experiments without
+  // introducing multiple prefs a la the autostart.N prefs.
+  if (Preferences::GetInt("dom.ipc.multiOptOut", 0) >=
+      nsIXULRuntime::E10S_MULTI_EXPERIMENT) {
+    return 1;
+  }
+
+  const char* optInPref = "dom.ipc.processCount";
+  uint32_t optInPrefValue = Preferences::GetInt(optInPref, 1);
+  return std::max(1u, optInPrefValue);
+}
+
+const char* PlatformBuildID() { return gToolkitBuildID; }
+
+}  // namespace mozilla
+
+void SetupErrorHandling(const char* progname) {
+#ifdef XP_WIN
+  /* On Windows XPSP3 and Windows Vista if DEP is configured off-by-default
+     we still want DEP protection: enable it explicitly and programmatically.
+
+     This function is not available on WinXPSP2 so we dynamically load it.
+  */
+
+  HMODULE kernel32 = GetModuleHandleW(L"kernel32.dll");
+  SetProcessDEPPolicyFunc _SetProcessDEPPolicy =
+      (SetProcessDEPPolicyFunc)GetProcAddress(kernel32, "SetProcessDEPPolicy");
+  if (_SetProcessDEPPolicy) _SetProcessDEPPolicy(PROCESS_DEP_ENABLE);
+#endif
+
+#ifdef XP_WIN
+  // Suppress the "DLL Foo could not be found" dialog, such that if dependent
+  // libraries (such as GDI+) are not preset, we gracefully fail to load those
+  // XPCOM components, instead of being ungraceful.
+  UINT realMode = SetErrorMode(0);
+  realMode |= SEM_FAILCRITICALERRORS;
+  // If XRE_NO_WINDOWS_CRASH_DIALOG is set, suppress displaying the "This
+  // application has crashed" dialog box.  This is mainly useful for
+  // automated testing environments, e.g. tinderbox, where there's no need
+  // for a dozen of the dialog boxes to litter the console
+  if (getenv("XRE_NO_WINDOWS_CRASH_DIALOG"))
+    realMode |= SEM_NOGPFAULTERRORBOX | SEM_NOOPENFILEERRORBOX;
+
+  SetErrorMode(realMode);
+
+#endif
+
+  InstallSignalHandlers(progname);
+
+  // Unbuffer stdout, needed for tinderbox tests.
+  setbuf(stdout, 0);
+}
+
+// Note: This function should not be needed anymore. See Bug 818634 for details.
+void OverrideDefaultLocaleIfNeeded() {
+  // Read pref to decide whether to override default locale with US English.
+  if (mozilla::Preferences::GetBool("javascript.use_us_english_locale",
+                                    false)) {
+    // Set the application-wide C-locale. Needed to resist fingerprinting
+    // of Date.toLocaleFormat(). We use the locale to "C.UTF-8" if possible,
+    // to avoid interfering with non-ASCII keyboard input on some Linux
+    // desktops. Otherwise fall back to the "C" locale, which is available on
+    // all platforms.
+    setlocale(LC_ALL, "C.UTF-8") || setlocale(LC_ALL, "C");
+  }
+}
+
+static bool gRunSelfAsContentProc = false;
+
+void XRE_EnableSameExecutableForContentProc() {
+  if (!PR_GetEnv("MOZ_SEPARATE_CHILD_PROCESS")) {
+    gRunSelfAsContentProc = true;
+  }
+}
+
+mozilla::BinPathType XRE_GetChildProcBinPathType(
+    GeckoProcessType aProcessType) {
+  MOZ_ASSERT(aProcessType != GeckoProcessType_Default);
+
+  if (!gRunSelfAsContentProc) {
+    return BinPathType::PluginContainer;
+  }
+
+  switch (aProcessType) {
+#define GECKO_PROCESS_TYPE(enum_value, enum_name, string_name, proc_typename, \
+                           process_bin_type, procinfo_typename,               \
+                           webidl_typename, allcaps_name)                     \
+  case GeckoProcessType_##enum_name:                                          \
+    return BinPathType::process_bin_type;
+#include "mozilla/GeckoProcessTypes.h"
+#undef GECKO_PROCESS_TYPE
+    default:
+      return BinPathType::PluginContainer;
+  }
+}
+
+// From mozglue/static/rust/lib.rs
+extern "C" void install_rust_hooks();
+
+struct InstallRustHooks {
+  InstallRustHooks() { install_rust_hooks(); }
+};
+
+InstallRustHooks sInstallRustHooks;
+
+#ifdef MOZ_ASAN_REPORTER
+void setASanReporterPath(nsIFile* aDir) {
+  nsCOMPtr<nsIFile> dir;
+  aDir->Clone(getter_AddRefs(dir));
+
+  dir->Append(u"asan"_ns);
+  nsresult rv = dir->Create(nsIFile::DIRECTORY_TYPE, 0700);
+  if (NS_WARN_IF(NS_FAILED(rv) && rv != NS_ERROR_FILE_ALREADY_EXISTS)) {
+    MOZ_CRASH("[ASan Reporter] Unable to create crash directory.");
+  }
+
+  dir->Append(u"ff_asan_log"_ns);
+
+#  ifdef XP_WIN
+  nsAutoString nspathW;
+  rv = dir->GetPath(nspathW);
+  NS_ConvertUTF16toUTF8 nspath(nspathW);
+#  else
+  nsAutoCString nspath;
+  rv = dir->GetNativePath(nspath);
+#  endif
+  if (NS_FAILED(rv)) {
+    MOZ_CRASH("[ASan Reporter] Unable to get native path for crash directory.");
+  }
+
+  __sanitizer_set_report_path(nspath.get());
+}
+#endif