path: root/dom/ipc/PContent.ipdl

/* -*- tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=2 et sw=2 tw=80: */
/* 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 protocol PBackgroundStarter;
include protocol PBrowser;
include protocol PCompositorManager;
include protocol PContentPermissionRequest;
include protocol PCycleCollectWithLogs;
include protocol PDocumentChannel;
include protocol PExtensions;
include protocol PExternalHelperApp;
include protocol PHandlerService;
include protocol PHal;
include protocol PHeapSnapshotTempFileHelper;
include protocol PProcessHangMonitor;
include protocol PImageBridge;
include protocol PRemotePrintJob;
include protocol PLoginReputation;
include protocol PMedia;
include protocol PNecko;
include protocol PStreamFilter;
include protocol PGMPContent;
include protocol PGMPService;
include protocol PGMP;
#ifdef MOZ_WEBSPEECH
include protocol PSpeechSynthesis;
#endif
include protocol PTestShell;
include protocol PRemoteSpellcheckEngine;
include protocol PWebBrowserPersistDocument;
#ifdef MOZ_WEBRTC
include protocol PWebrtcGlobal;
#endif
include protocol PWindowGlobal;
include protocol PURLClassifier;
include protocol PURLClassifierLocal;
include protocol PVRManager;
include protocol PRemoteDecoderManager;
include protocol PProfiler;
include protocol PScriptCache;
include protocol PSessionStorageObserver;
include protocol PBenchmarkStorage;
include DOMTypes;
include WindowGlobalTypes;
include IPCBlob;
include IPCStream;
include PPrintingTypes;
include PTabContext;
include ProtocolTypes;
include PBackgroundSharedTypes;
include PContentPermission;
include GraphicsMessages;
include MemoryReportTypes;
include ClientIPCTypes;
include HangTypes;
include PrefsTypes;
include NeckoChannelParams;
include PSMIPCTypes;
include LookAndFeelTypes;

#if defined(MOZ_SANDBOX) && defined(MOZ_DEBUG) && defined(ENABLE_TESTS)
include protocol PSandboxTesting;
#endif

include "ipc/MediaControlIPC.h";
include "mozilla/AntiTrackingIPCUtils.h";
include "mozilla/GfxMessageUtils.h";
include "mozilla/dom/BindingIPCUtils.h";
include "mozilla/dom/CSPMessageUtils.h";
include "mozilla/dom/DocShellMessageUtils.h";
include "mozilla/dom/FeaturePolicyUtils.h";
include "mozilla/dom/MediaSessionIPCUtils.h";
include "mozilla/dom/PageLoadEventUtils.h";
include "mozilla/dom/ReferrerInfoUtils.h";
include "mozilla/glean/GleanMetrics.h";
include "mozilla/ipc/ByteBufUtils.h";
include "mozilla/ipc/TransportSecurityInfoUtils.h";
include "mozilla/ipc/URIUtils.h";
include "mozilla/PermissionDelegateIPCUtils.h";

[RefCounted] using class nsIDOMGeoPosition from "nsGeoPositionIPCSerialiser.h";
[RefCounted] using class nsIAlertNotification from "mozilla/AlertNotificationIPCSerializer.h";

using struct ChromePackage from "mozilla/chrome/RegistryMessageUtils.h";
using struct SubstitutionMapping from "mozilla/chrome/RegistryMessageUtils.h";
using struct OverrideMapping from "mozilla/chrome/RegistryMessageUtils.h";
using base::ProcessId from "base/process.h";
using struct IPC::Permission from "mozilla/net/NeckoMessageUtils.h";
using mozilla::a11y::IHandlerControlHolder from "mozilla/a11y/IPCTypes.h";
using mozilla::dom::NativeThreadId from "mozilla/dom/NativeThreadId.h";
using mozilla::hal::ProcessPriority from "mozilla/HalTypes.h";
using mozilla::gfx::IntSize from "mozilla/gfx/2D.h";
using mozilla::gfx::SurfaceFormat from "mozilla/gfx/Types.h";
using mozilla::dom::TabId from "mozilla/dom/ipc/IdType.h";
using mozilla::dom::ContentParentId from "mozilla/dom/ipc/IdType.h";
using mozilla::LayoutDeviceIntPoint from "Units.h";
using mozilla::ImagePoint from "Units.h";
using mozilla::ImageIntSize from "Units.h";
using mozilla::widget::ThemeChangeKind from "mozilla/widget/WidgetMessageUtils.h";
using class mozilla::dom::MessagePort from "mozilla/dom/MessagePort.h";
using class mozilla::dom::ipc::StructuredCloneData from "mozilla/dom/ipc/StructuredCloneData.h";
using mozilla::OriginAttributes from "mozilla/ipc/BackgroundUtils.h";
using struct mozilla::layers::TextureFactoryIdentifier from "mozilla/layers/CompositorTypes.h";
using mozilla::layers::CompositorOptions from "mozilla/layers/CompositorOptions.h";
using mozilla::layers::LayersId from "mozilla/layers/LayersTypes.h";
using mozilla::Telemetry::HistogramAccumulation from "mozilla/TelemetryComms.h";
using mozilla::Telemetry::KeyedHistogramAccumulation from "mozilla/TelemetryComms.h";
using mozilla::Telemetry::ScalarAction from "mozilla/TelemetryComms.h";
using mozilla::Telemetry::KeyedScalarAction from "mozilla/TelemetryComms.h";
using mozilla::Telemetry::DynamicScalarDefinition from "mozilla/TelemetryComms.h";
using mozilla::Telemetry::ChildEventData from "mozilla/TelemetryComms.h";

#if defined(XP_WIN)
[MoveOnly] using mozilla::UntrustedModulesData from "mozilla/UntrustedModulesData.h";
[MoveOnly] using mozilla::ModulePaths from "mozilla/UntrustedModulesData.h";
[MoveOnly] using mozilla::ModulesMapResult from "mozilla/UntrustedModulesData.h";
#endif  // defined(XP_WIN)

using mozilla::Telemetry::DiscardedData from "mozilla/TelemetryComms.h";
using mozilla::glean::perf::PageLoadExtra from "mozilla/glean/GleanMetrics.h";
[MoveOnly] using mozilla::CrossProcessMutexHandle from "mozilla/ipc/CrossProcessMutex.h";
using mozilla::dom::MaybeDiscardedBrowsingContext from "mozilla/dom/BrowsingContext.h";
using mozilla::dom::BrowsingContextTransaction from "mozilla/dom/BrowsingContext.h";
using mozilla::dom::BrowsingContextInitializer from "mozilla/dom/BrowsingContext.h";
using mozilla::dom::PermitUnloadResult from "nsIContentViewer.h";
using mozilla::dom::MaybeDiscardedWindowContext from "mozilla/dom/WindowContext.h";
using mozilla::dom::WindowContextTransaction from "mozilla/dom/WindowContext.h";
[MoveOnly] using base::SharedMemoryHandle from "base/shared_memory.h";
using mozilla::fontlist::Pointer from "SharedFontList.h";
using gfxSparseBitSet from "gfxFontUtils.h";
using FontVisibility from "gfxFontEntry.h";
using mozilla::dom::MediaControlAction from "mozilla/dom/MediaControlKeySource.h";
using mozilla::dom::MediaPlaybackState from "mozilla/dom/MediaPlaybackStatus.h";
using mozilla::dom::MediaAudibleState from "mozilla/dom/MediaPlaybackStatus.h";
using mozilla::dom::MediaMetadataBase from "mozilla/dom/MediaMetadata.h";
using mozilla::dom::MediaSessionAction from "mozilla/dom/MediaSessionBinding.h";
using mozilla::dom::MediaSessionPlaybackState from "mozilla/dom/MediaSessionBinding.h";
using mozilla::dom::PositionState from "mozilla/dom/MediaSession.h";
using mozilla::dom::ServiceWorkerShutdownState::Progress from "mozilla/dom/ServiceWorkerShutdownState.h";
using mozilla::ContentBlockingNotifier::StorageAccessPermissionGrantedReason from "mozilla/ContentBlockingNotifier.h";
using mozilla::ContentBlockingNotifier::BlockingDecision from "mozilla/ContentBlockingNotifier.h";
using mozilla::StorageAccessAPIHelper::StorageAccessPromptChoices from "mozilla/StorageAccessAPIHelper.h";
using JSActorMessageKind from "mozilla/dom/JSActor.h";
using JSActorMessageMeta from "mozilla/dom/PWindowGlobal.h";
using mozilla::PermissionDelegateHandler::DelegatedPermissionList from "mozilla/PermissionDelegateHandler.h";
[RefCounted] using class nsILayoutHistoryState from "nsILayoutHistoryState.h";
using class mozilla::dom::SessionHistoryInfo from "mozilla/dom/SessionHistoryEntry.h";
using struct nsPoint from "nsPoint.h";
using struct mozilla::dom::LoadingSessionHistoryInfo from "mozilla/dom/SessionHistoryEntry.h";
using mozilla::media::MediaCodecsSupported from "MediaCodecsSupport.h";
using mozilla::RemoteDecodeIn from "mozilla/RemoteDecoderManagerChild.h";
using mozilla::dom::PerformanceTimingData from "mozilla/dom/PerformanceTiming.h";
[RefCounted] using mozilla::dom::FeaturePolicy from "mozilla/dom/FeaturePolicy.h";
using Wireframe from "mozilla/dom/DocumentBinding.h";
using mozilla::PerfStats::MetricMask from "mozilla/PerfStats.h";
[RefCounted] using class nsIX509Cert from "nsIX509Cert.h";

union ChromeRegistryItem
{
    ChromePackage;
    OverrideMapping;
    SubstitutionMapping;
};

namespace mozilla {
namespace dom {

// SetXPCOMProcessAttributes passes an array of font data to the child,
// but each platform needs different details so we have platform-specific
// versions of the SystemFontListEntry type:
#if defined(ANDROID)
// Used on Android to pass the list of fonts on the device
// to the child process
struct SystemFontListEntry {
    nsCString familyName;
    nsCString faceName;
    nsCString filepath;
    uint32_t  weightRange;
    uint32_t  stretchRange;
    uint32_t  styleRange;
    uint8_t   index;
    FontVisibility visibility;
};
#elif defined(XP_MACOSX)
// Used on Mac OS X to pass the list of font families (not faces)
// from chrome to content processes.
// The entryType field distinguishes several types of font family
// record; see gfxMacPlatformFontList.h for values and meaning.
struct SystemFontListEntry {
    nsCString familyName;
    FontVisibility visibility;
    uint8_t   entryType;
};
#else
// Used on Linux to pass list of font patterns from chrome to content.
// (Unused on Windows, but there needs to be a definition of the type.)
struct SystemFontListEntry {
    nsCString pattern;
    bool      appFontFamily;
};
#endif

#ifdef MOZ_WIDGET_GTK
struct SystemFontOptions {
    int32_t antialias; // cairo_antialias_t
    int32_t subpixelOrder; // cairo_subpixel_order_t
    int32_t hintStyle; // cairo_hint_style_t
    int32_t lcdFilter; // cairo_lcd_filter_t
};
#endif

struct SystemFontList {
    SystemFontListEntry[] entries;
#ifdef MOZ_WIDGET_GTK
    SystemFontOptions options;
#endif
};

union SystemParameterValue {
  bool;
  float;
};

struct ClipboardCapabilities {
  bool supportsSelectionClipboard;
  bool supportsFindClipboard;
};

union FileDescOrError {
    FileDescriptor;
    nsresult;
};

struct DomainPolicyClone
{
    bool        active;
    nsIURI[] blocklist;
    nsIURI[] allowlist;
    nsIURI[] superBlocklist;
    nsIURI[] superAllowlist;
};

struct AndroidSystemInfo
{
    nsString device;
    nsString manufacturer;
    nsString release_version;
    nsString hardware;
    uint32_t sdk_version;
    bool     isTablet;
};

struct GetFilesResponseSuccess
{
  IPCBlob[] blobs;
};

struct GetFilesResponseFailure
{
  nsresult errorCode;
};

union GetFilesResponseResult
{
  GetFilesResponseSuccess;
  GetFilesResponseFailure;
};

struct BlobURLRegistrationData
{
  nsCString url;
  IPCBlob blob;
  nsIPrincipal principal;
  nsID? agentClusterId;
  bool revoked;
};

struct JSWindowActorEventDecl
{
  nsString name;
  bool capture;
  bool systemGroup;
  bool allowUntrusted;
  bool? passive;
  bool createActor;
};

struct JSWindowActorInfo
{
  nsCString name;
  bool allFrames;

  // True if `url` is for ESM.
  // False if `url` is for JSM or nothing.
  bool isESModule;

  // The module of the url.
  nsCString? url;

  JSWindowActorEventDecl[] events;

  // Observer notifications this actor listens to.
  nsCString[] observers;
  nsString[] matches;
  nsCString[] remoteTypes;
  nsString[] messageManagerGroups;
};

struct JSProcessActorInfo
{
    // The name of the actor.
    nsCString name;

    // True if `url` is for ESM.
    // False if `url` is for JSM or nothing.
    bool isESModule;

    // The module of the url.
    nsCString? url;

    // Observer notifications this actor listens to.
    nsCString[] observers;
    nsCString[] remoteTypes;
};

struct GMPAPITags
{
    nsCString api;
    nsCString[] tags;
};

struct GMPCapabilityData
{
    nsCString name;
    nsCString version;
    GMPAPITags[] capabilities;
};

struct L10nFileSourceDescriptor {
  nsCString name;
  nsCString metasource;
  nsCString[] locales;
  nsCString prePath;
  nsCString[] index;
};

struct XPCOMInitData
{
    bool isOffline;
    bool isConnected;
    int32_t captivePortalState;
    bool isLangRTL;
    bool haveBidiKeyboards;
    nsCString[] dictionaries;
    ClipboardCapabilities clipboardCaps;
    DomainPolicyClone domainPolicy;
    nsIURI userContentSheetURL;
    GfxVarUpdate[] gfxNonDefaultVarUpdates;
    ContentDeviceData contentDeviceData;
    GfxInfoFeatureStatus[] gfxFeatureStatus;
    nsCString[] appLocales;
    nsCString[] requestedLocales;
    L10nFileSourceDescriptor[] l10nFileSources;
    DynamicScalarDefinition[] dynamicScalarDefs;
    MetricMask perfStatsMask;
    nsCString trrDomain;
};

struct VisitedQueryResult
{
    nsIURI uri;
    bool visited;
};

struct StringBundleDescriptor
{
    nsCString bundleURL;
    FileDescriptor mapFile;
    uint32_t mapSize;
};

struct IPCURLClassifierFeature
{
    nsCString featureName;
    nsCString[] tables;
    nsCString exceptionHostList;
};

// Transport structure for Notifications API notifications
// (https://developer.mozilla.org/en-US/docs/Web/API/notification) instances
// used exclusively by the NotificationEvent PContent method.
struct NotificationEventData
{
    nsCString originSuffix;
    nsCString scope;
    nsString ID;
    nsString title;
    nsString dir;
    nsString lang;
    nsString body;
    nsString tag;
    nsString icon;
    nsString data;
    nsString behavior;
};

struct PostMessageData
{
    MaybeDiscardedBrowsingContext source;
    nsString origin;
    nsString targetOrigin;
    nsIURI targetOriginURI;
    nsIPrincipal callerPrincipal;
    nsIPrincipal subjectPrincipal;
    nsIURI callerURI;
    bool isFromPrivateWindow;
    nsCString scriptLocation;
    uint64_t innerWindowId;
};

union SyncedContextInitializer
{
    BrowsingContextInitializer;
    WindowContextInitializer;
};

union BlobURLDataRequestResult
{
  IPCBlob;
  nsresult;
};

struct TextRecognitionQuad {
    float confidence;
    nsString string;
    ImagePoint[] points;
};

struct TextRecognitionResult {
    TextRecognitionQuad[] quads;
};

union TextRecognitionResultOrError {
    TextRecognitionResult;
    nsCString;
};

struct IPCImage {
    BigBuffer data;
    uint32_t stride;
    SurfaceFormat format;
    ImageIntSize size;
};

union IPCDataTransferOrError {
    IPCDataTransfer;
    nsresult;
};

/**
 * The PContent protocol is a top-level protocol between the UI process
 * and a content process. There is exactly one PContentParent/PContentChild pair
 * for each content process.
 */
[ManualDealloc, NestedUpTo=inside_cpow, NeedsOtherPid]
sync protocol PContent
{
    manages PBrowser;
    manages PContentPermissionRequest;
    manages PCycleCollectWithLogs;
    manages PExtensions;
    manages PExternalHelperApp;
    manages PHal;
    manages PHandlerService;
    manages PHeapSnapshotTempFileHelper;
    manages PRemotePrintJob;
    manages PMedia;
    manages PNecko;
#ifdef MOZ_WEBSPEECH
    manages PSpeechSynthesis;
#endif
    manages PTestShell;
    manages PRemoteSpellcheckEngine;
    manages PWebBrowserPersistDocument;
#ifdef MOZ_WEBRTC
    manages PWebrtcGlobal;
#endif
    manages PURLClassifier;
    manages PURLClassifierLocal;
    manages PScriptCache;
    manages PLoginReputation;
    manages PSessionStorageObserver;
    manages PBenchmarkStorage;

    // Depending on exactly how the new browser is being created, it might be
    // created from either the child or parent process!
    //
    // The child creates the PBrowser as part of
    // BrowserChild::BrowserFrameProvideWindow (which happens when the child's
    // content calls window.open()), and the parent creates the PBrowser as part
    // of ContentParent::CreateBrowser.
    //
    // When the parent constructs a PBrowser, the child trusts the attributes it
    // receives from the parent.  In that case, the context should be
    // FrameIPCTabContext.
    //
    // When the child constructs a PBrowser, the parent doesn't trust the
    // attributes it receives from the child.  In this case, context must have
    // type PopupIPCTabContext.  The parent checks that if the opener is a
    // browser element, the context is also for a browser element.
    //
    // If |sameTabGroupAs| is non-zero, the new tab should go in the same
    // TabGroup as |sameTabGroupAs|. This parameter should always be zero
    // for PBrowser messages sent from the child to the parent.
    //
    // Separate messages are used for the parent and child side constructors due
    // to the differences in data and actor setup required.
    //
    // Keep the last 3 attributes in sync with GetProcessAttributes!
parent:
    async ConstructPopupBrowser(ManagedEndpoint<PBrowserParent> browserEp,
                                ManagedEndpoint<PWindowGlobalParent> windowEp,
                                TabId tabId, IPCTabContext context,
                                WindowGlobalInit windowInit,
                                uint32_t chromeFlags);

    // TODO: Do I need to make this return something to watch for completion?
    // Guess we'll see how we end up triggering the actual print, for preview
    // this should be enough...
    async CloneDocumentTreeInto(MaybeDiscardedBrowsingContext aSourceBc,
                                MaybeDiscardedBrowsingContext aTargetBc,
                                PrintData aPrintData);

    async UpdateRemotePrintSettings(MaybeDiscardedBrowsingContext aBc,
                                    PrintData aPrintData);

    async PExtensions();

child:
    async ConstructBrowser(ManagedEndpoint<PBrowserChild> browserEp,
                           ManagedEndpoint<PWindowGlobalChild> windowEp,
                           TabId tabId,
                           IPCTabContext context,
                           WindowGlobalInit windowInit,
                           uint32_t chromeFlags, ContentParentId cpId,
                           bool isForBrowser, bool isTopLevel);

both:
    // For parent->child, aBrowser must be non-null; aContext can
    // be null to indicate the browser's current root document, or non-null
    // to persist a subdocument.  For child->parent, arguments are
    // ignored and should be null.
    async PWebBrowserPersistDocument(nullable PBrowser aBrowser,
                                     MaybeDiscardedBrowsingContext aContext);

    async RawMessage(JSActorMessageMeta aMetadata, ClonedMessageData? aData,
                     ClonedMessageData? aStack);

child:
    async InitGMPService(Endpoint<PGMPServiceChild> service);
    async InitProcessHangMonitor(Endpoint<PProcessHangMonitorChild> hangMonitor);
    async InitProfiler(Endpoint<PProfilerChild> aEndpoint);

    // Give the content process its endpoints to the compositor.
    async InitRendering(
      Endpoint<PCompositorManagerChild> compositor,
      Endpoint<PImageBridgeChild> imageBridge,
      Endpoint<PVRManagerChild> vr,
      Endpoint<PRemoteDecoderManagerChild> video,
      uint32_t[] namespaces);

    // Re-create the rendering stack using the given endpoints. This is sent
    // after the compositor process has crashed. The new endpoints may be to a
    // newly launched GPU process, or the compositor thread of the UI process.
    async ReinitRendering(
      Endpoint<PCompositorManagerChild> compositor,
      Endpoint<PImageBridgeChild> bridge,
      Endpoint<PVRManagerChild> vr,
      Endpoint<PRemoteDecoderManagerChild> video,
      uint32_t[] namespaces);

    async NetworkLinkTypeChange(uint32_t type);
    async SocketProcessCrashed();

    // Re-create the rendering stack for a device reset.
    async ReinitRenderingForDeviceReset();

    /**
     * Enable system-level sandboxing features, if available.  Can
     * usually only be performed zero or one times.  The child may
     * abnormally exit if this fails; the details are OS-specific.
     */
    async SetProcessSandbox(FileDescriptor? aBroker);

    async RequestMemoryReport(uint32_t generation,
                              bool anonymize,
                              bool minimizeMemoryUsage,
                              FileDescriptor? DMDFile)
        returns (uint32_t aGeneration);

    async RequestPerformanceMetrics(nsID aID);

#if defined(XP_WIN)
    /**
     * Used by third-party modules telemetry (aka "untrusted modules" telemetry)
     * to pull data from content processes.
     */
    async GetUntrustedModulesData() returns (UntrustedModulesData? data);

    /**
    * This method is used to notifty a child process to start
    * processing module loading events in UntrustedModulesProcessor.
    * This should be called when the parent process has gone idle.
    */
    async UnblockUntrustedModulesThread();
#endif  // defined(XP_WIN)

    /**
     * Communication between the PuppetBidiKeyboard and the actual
     * BidiKeyboard hosted by the parent
     */
    async BidiKeyboardNotify(bool isLangRTL, bool haveBidiKeyboards);

    /**
     * Dump this process's GC and CC logs to the provided files.
     *
     * For documentation on the other args, see dumpGCAndCCLogsToFile in
     * nsIMemoryInfoDumper.idl
     */
    async PCycleCollectWithLogs(bool dumpAllTraces,
                                FileDescriptor gcLog,
                                FileDescriptor ccLog);

    async PTestShell();

    async PScriptCache(FileDescOrError cacheFile, bool wantCacheData);

    async RegisterChrome(ChromePackage[] packages, SubstitutionMapping[] substitutions,
                         OverrideMapping[] overrides, nsCString locale, bool reset);
    async RegisterChromeItem(ChromeRegistryItem item);

    async ClearImageCacheFromPrincipal(nsIPrincipal aPrincipal);

    async ClearImageCacheFromBaseDomain(nsCString aBaseDomain);

    async ClearImageCache(bool privateLoader, bool chrome);

    async ClearStyleSheetCache(nsIPrincipal? aForPrincipal,
                               nsCString? aBaseDomain);

    async SetOffline(bool offline);
    async SetConnectivity(bool connectivity);
    async SetCaptivePortalState(int32_t aState);

    async NotifyVisited(VisitedQueryResult[] uri);

    /**
     * Tell the child that the system theme has changed, and that a repaint is
     * necessary.
     */
    async ThemeChanged(FullLookAndFeel lookAndFeelData, ThemeChangeKind aKind);

    async PreferenceUpdate(Pref pref);
    async VarUpdate(GfxVarUpdate var);

    async UpdatePerfStatsCollectionMask(uint64_t aMask);
    async CollectPerfStatsJSON() returns (nsCString aStats);

    async CollectScrollingMetrics() returns (uint32_t pixelsScrolled, uint32_t scrollDurationMS);

    async NotifyAlertsObserver(nsCString topic, nsString data);

    async GeolocationUpdate(nsIDOMGeoPosition aPosition);

    async GeolocationError(uint16_t errorCode);

    async UpdateDictionaryList(nsCString[] dictionaries);

    async UpdateFontList(SystemFontList fontList);

    /**
     * The shared font list has been updated by the parent, so child processes
     * should globally reflow everything to pick up new character coverage etc.
     * If aFullRebuild is true, child processes must discard and recreate
     * their mappings to the shmem blocks, as those are no longer valid.
     * This message has raised priority so that it will take precedence over
     * vsync messages to the child.
     */
    [Priority=mediumhigh] async RebuildFontList(bool aFullRebuild);

    /**
     * The shared font list has been modified, potentially adding matches
     * for src:local() names that were previously not known, so content
     * may need to be reflowed.
     */
    async FontListChanged();

    /**
     * The font list or prefs have been updated in such a way that we might need
     * to do a reflow and maybe reframe.
     */
    async ForceGlobalReflow(bool aNeedsReframe);

    /**
     * A new shmem block has been added to the font list; the child process
     * should map the new block and add to its index.
     */
    async FontListShmBlockAdded(uint32_t aGeneration, uint32_t aIndex,
                                SharedMemoryHandle aHandle);

    async UpdateAppLocales(nsCString[] appLocales);
    async UpdateRequestedLocales(nsCString[] requestedLocales);

    /**
     * The system timezone has changed; the child process should ensure that
     * calls to get the default timezone return the new value.
     */
    async SystemTimezoneChanged();

    async UpdateL10nFileSources(L10nFileSourceDescriptor[] sources);

    async RegisterStringBundles(StringBundleDescriptor[] stringBundles);

    async UpdateSharedData(FileDescriptor mapFile, uint32_t aSize,
                           IPCBlob[] blobs,
                           nsCString[] changedKeys);

    // nsIPermissionManager messages
    async AddPermission(Permission permission);
    async RemoveAllPermissions();

    async FlushMemory(nsString reason);

    async ApplicationBackground();
    async ApplicationForeground();
    async GarbageCollect();
    async CycleCollect();
    async UnlinkGhosts();

    /**
     * Start accessibility engine in content process.
     * @param aTid is the thread ID of the chrome process main thread. Only used
     *             on Windows; pass 0 on other platforms.
     * @param aMsaaID is an a11y-specific unique id for the content process
     *                that is generated by the chrome process. Only used on
     *                Windows; pass 0 on other platforms.
     */
    async ActivateA11y(uint32_t aMainChromeTid, uint32_t aMsaaID);

    /**
     * Shutdown accessibility engine in content process (if not in use).
     */
    async ShutdownA11y();

    async AppInfo(nsCString version, nsCString buildID, nsCString name, nsCString UAName,
                  nsCString ID, nsCString vendor, nsCString sourceURL, nsCString updateURL);

    /**
     * Send the remote type associated with the content process.
     */
    async RemoteType(nsCString aRemoteType, nsCString aProfile);

    /**
     * Send BlobURLRegistrationData to child process.
     */
    async InitBlobURLs(BlobURLRegistrationData[] registrations);

    /**
     * Send JS{Content, Window}ActorInfos to child process.
     */
    async InitJSActorInfos(JSProcessActorInfo[] aContentInfos, JSWindowActorInfo[] aWindowInfos);

    /**
     * Unregister a previously registered JSWindowActor in the child process.
     */
    async UnregisterJSWindowActor(nsCString name);

    /**
     * Unregister a previously registered JSProcessActor in the child process.
     */
    async UnregisterJSProcessActor(nsCString name);

    async SetXPCOMProcessAttributes(XPCOMInitData xpcomInit,
                                    StructuredCloneData initialData,
                                    FullLookAndFeel lookAndFeeldata,
                                    /* used on MacOSX/Linux/Android only: */
                                    SystemFontList systemFontList,
                                    SharedMemoryHandle? sharedUASheetHandle,
                                    uintptr_t sharedUASheetAddress,
                                    SharedMemoryHandle[] sharedFontListBlocks,
                                    bool aIsStartingUp);

    // Notify child that last-pb-context-exited notification was observed
    async LastPrivateDocShellDestroyed();

    async NotifyProcessPriorityChanged(ProcessPriority priority);
    async MinimizeMemoryUsage();

    /**
     * Used to manage nsIStyleSheetService across processes.
     */
    async LoadAndRegisterSheet(nsIURI uri, uint32_t type);
    async UnregisterSheet(nsIURI uri, uint32_t type);

    /**
     * Notify idle observers in the child
     */
    async NotifyIdleObserver(uint64_t observerId, nsCString topic, nsString str);

    async InvokeDragSession(MaybeDiscardedWindowContext aContext,
                            IPCDataTransfer[] transfers, uint32_t action);

    async EndDragSession(bool aDoneDrag, bool aUserCancelled,
                         LayoutDeviceIntPoint aDragEndPoint,
                         uint32_t aKeyModifiers,
                         uint32_t aDropEffect);

    async DomainSetChanged(uint32_t aSetType, uint32_t aChangeType, nsIURI aDomain);

    /**
     * Notify the child that it will soon be asked to shutdown.
     * This is sent with high priority right before the normal shutdown.
     */
    [Priority=control] async ShutdownConfirmedHP();

    /**
     * Notify the child to shutdown. The child will in turn call FinishShutdown
     * and let the parent close the channel.
     */
    async Shutdown();

    async LoadProcessScript(nsString url);

    /**
     * Requests a full native update of a native plugin child window. This is
     * a Windows specific call.
     */
    async UpdateWindow(uintptr_t aChildId);

    /**
     * Notify the child that cache is emptied.
     */
    async NotifyEmptyHTTPCache();

    /**
     * Send a `push` event without data to a service worker in the child.
     */
    async Push(nsCString scope, nsIPrincipal principal, nsString messageId);

    /**
     * Send a `push` event with data to a service worker in the child.
     */
    async PushWithData(nsCString scope, nsIPrincipal principal,
                       nsString messageId, uint8_t[] data);

    /**
     * Send a `pushsubscriptionchange` event to a service worker in the child.
     */
    async PushSubscriptionChange(nsCString scope, nsIPrincipal principal);

    async GetFilesResponse(nsID aID, GetFilesResponseResult aResult);

    async BlobURLRegistration(nsCString aURI, IPCBlob aBlob,
                              nsIPrincipal aPrincipal,
                              nsID? aAgentClusterId);

    async BlobURLUnregistration(nsCString aURI);

    async GMPsChanged(GMPCapabilityData[] capabilities);


    async ProvideAnonymousTemporaryFile(uint64_t aID, FileDescOrError aFD);

    async SetPermissionsWithKey(nsCString aPermissionKey, Permission[] aPermissions);

    async RefreshScreens(ScreenDetails[] aScreens);

    async ShareCodeCoverageMutex(CrossProcessMutexHandle handle);
    async FlushCodeCoverageCounters() returns (bool unused);

    /*
     * IPC message to enable the input event queue on the main thread of the
     * content process.
     */
    async SetInputEventQueueEnabled();

    /*
     * IPC message to flush the input event queue on the main thread of the
     * content process.
     *
     * When the ContentParent stops sending the input event with input priority,
     * there may be some pending events in the input event queue and normal
     * event queue. Here is a possible scenario.
     * R: Runnables.
     * D: Enable the input priority event.
     * E: Disable the input priority evnet.
     *
     *                     D       E
     * Normal Queue: R1      R2      R3
     * Input Queue:     II      I2      I3
     *
     * To avoid the newly added normal events (e.g. R2, which may be an input
     * event) preempt the pending input events (e.g. I1), or the newly added
     * input events (e.g. I3) preempt the pending normal events (e.g. R2), we
     * have to flush all pending events before enabling and disabling the input
     * priority event.
     *
     * To flush the normal event queue and the input event queue, we use three
     * IPC messages as the followings.
     * FI: Flush the input queue.
     * SI: Suspend the input queue.
     * RI: Resume the input queue.
     *
     * Normal Queue: R1    FI    RI R2   FI    RI R3
     * Input Queue:     II    SI      I2    SI       I3
     *
     * When the flush input request is processed before the other two requests,
     * we consume all input events until the suspend request. After handling the
     * suspend request, we stop consuming the input events until the resume
     * request to make sure we consume all pending normal events.
     *
     * If we process the suspend request before the other two requests, we
     * ignore the flush request and consume all pending normal events until the
     * resume request.
     */
    async FlushInputEventQueue();

    /*
     * IPC message to resume consuming the pending events in the input event
     * queue.
     */
    async ResumeInputEventQueue();

    /*
     * IPC message to suspend consuming the pending events in the input event
     * queue.
     */
    [Priority=input] async SuspendInputEventQueue();

    /*
     * IPC message to propagate dynamic scalar definitions, added after the
     * content process is spawned, from the parent to the child.
     * Dynamic scalar definitions added at the process startup are handled
     * using the |TelemetryIPC::AddDynamicScalarDefinitions| functions.
     */
    async AddDynamicScalars(DynamicScalarDefinition[] definitions);

    // This message is sent to content processes, and triggers the creation of a
    // new HttpChannelChild that will be connected to the parent channel
    // represented by registrarId.
    // This is on PContent not PNecko, as PNecko may not be initialized yet.
    // The returned loadInfo needs to be set on the channel - since the channel
    // moved to a new process it now has different properties.

    async CrossProcessRedirect(RedirectToRealChannelArgs args,
                               Endpoint<PStreamFilterParent>[] aEndpoint)
        returns (nsresult rv);

    /**
    * This method is used to notifty content process to start delayed autoplay
    * media via browsing context.
    */
    async StartDelayedAutoplayMediaComponents(MaybeDiscardedBrowsingContext aContext);

    /**
     * This method is used to dispatch MediaControlAction to content process in
     * order to control media within a specific browsing context tree.
     */
    async UpdateMediaControlAction(MaybeDiscardedBrowsingContext aContext,
                                   MediaControlAction aAction);

    // Begin subscribing to a new BrowsingContextGroup, sending down the current
    // value for every individual BrowsingContext.
    async RegisterBrowsingContextGroup(uint64_t aGroupId, SyncedContextInitializer[] aInits);

    // The BrowsingContextGroup has been destroyed in the parent process. The
    // content process won't destroy the group until it receives this message or
    // during shutdown.
    //
    // When the content process receives this message, all contexts in the group
    // should have already been destroyed.
    async DestroyBrowsingContextGroup(uint64_t aGroupId);

#if defined(MOZ_SANDBOX) && defined(MOZ_DEBUG) && defined(ENABLE_TESTS)
    // Initialize top-level actor for testing content process sandbox.
    async InitSandboxTesting(Endpoint<PSandboxTestingChild> aEndpoint);
#endif

    async LoadURI(MaybeDiscardedBrowsingContext aContext, nsDocShellLoadState aLoadState, bool aSetNavigating)
        returns (bool aSuccess);

    async InternalLoad(nsDocShellLoadState aLoadState);

    async DisplayLoadError(MaybeDiscardedBrowsingContext aContext, nsString aURI);

    async GoBack(MaybeDiscardedBrowsingContext aContext, int32_t? aCancelContentJSEpoch, bool aRequireUserInteraction, bool aUserActivation);
    async GoForward(MaybeDiscardedBrowsingContext aContext, int32_t? aCancelContentJSEpoch, bool aRequireUserInteraction, bool aUserActivation);
    async GoToIndex(MaybeDiscardedBrowsingContext aContext, int32_t aIndex, int32_t? aCancelContentJSEpoch, bool aUserActivation);
    async Reload(MaybeDiscardedBrowsingContext aContext, uint32_t aReloadFlags);
    async StopLoad(MaybeDiscardedBrowsingContext aContext, uint32_t aStopFlags);

    async OnAllowAccessFor(MaybeDiscardedBrowsingContext aParentContext,
                           nsCString aTrackingOrigin,
                           uint32_t aCookieBehavior,
                           StorageAccessPermissionGrantedReason aReason);

    async OnContentBlockingDecision(MaybeDiscardedBrowsingContext aContext,
                                    BlockingDecision aReason,
                                    uint32_t aRejectedReason);

    /**
     * Abort orientationPendingPromises for documents in the child which
     * are part of a BrowsingContextGroup.
     */
    async AbortOrientationPendingPromises(MaybeDiscardedBrowsingContext aContext);

    async HistoryCommitIndexAndLength(MaybeDiscardedBrowsingContext aContext,
                                      uint32_t aIndex, uint32_t aLength,
                                      nsID aChangeID);

    async GetLayoutHistoryState(MaybeDiscardedBrowsingContext aContext)
        returns (nsILayoutHistoryState aState, Wireframe? aWireframe);

    async DispatchLocationChangeEvent(MaybeDiscardedBrowsingContext aContext);

    // Dispatches a "beforeunload" event to each in-process content window in the
    // subtree beginning at `aStartingAt`, and returns the result as documented in
    // the `PermitUnloadResult` enum.
    async DispatchBeforeUnloadToSubtree(MaybeDiscardedBrowsingContext aStartingAt)
        returns (PermitUnloadResult result);

    // Update the cached list of codec supported in the given process.
    async UpdateMediaCodecsSupported(RemoteDecodeIn aLocation, MediaCodecsSupported aSupported);

    // Send the list of the supported mimetypes in the given process. GeckoView-specific
    async DecoderSupportedMimeTypes(nsCString[] supportedTypes);

    // Used to initialize the global variable in content processes with the
    // latched value in the parent process. See dom/LocalStorageCommon.h for more
    // details.
    async InitNextGenLocalStorageEnabled(bool enabled);

  async PRemotePrintJob();

parent:

    async SynchronizeLayoutHistoryState(MaybeDiscardedBrowsingContext aContext,
                                        nsILayoutHistoryState aState);

    async SessionHistoryEntryTitle(MaybeDiscardedBrowsingContext aContext,
                                   nsString aTitle);

    async SessionHistoryEntryScrollRestorationIsManual(MaybeDiscardedBrowsingContext aContext,
                                                       bool aIsManual);
    async SessionHistoryEntryScrollPosition(MaybeDiscardedBrowsingContext aContext,
                                            int32_t aX, int32_t aY);

    async SessionHistoryEntryCacheKey(MaybeDiscardedBrowsingContext aContext,
                                      uint32_t aCacheKey);

    async SessionHistoryEntryStoreWindowNameInContiguousEntries(MaybeDiscardedBrowsingContext aContext,
                                                                nsString aName);

    async SessionHistoryEntryWireframe(MaybeDiscardedBrowsingContext aContext,
                                       Wireframe aWireframe);

    async GetLoadingSessionHistoryInfoFromParent(MaybeDiscardedBrowsingContext aContext)
        returns (LoadingSessionHistoryInfo? aLoadingInfo);

    async RemoveFromBFCache(MaybeDiscardedBrowsingContext aContext);

    async InitBackground(Endpoint<PBackgroundStarterParent> aEndpoint);

    async CreateGMPService();

    async InitStreamFilter(uint64_t channelId, nsString addonId)
        returns (Endpoint<PStreamFilterChild> aEndpoint);

    async PRemoteSpellcheckEngine();

    async InitCrashReporter(NativeThreadId tid);

    sync IsSecureURI(nsIURI aURI, OriginAttributes aOriginAttributes)
        returns (bool isSecureURI);

    async AccumulateMixedContentHSTS(nsIURI aURI, bool aActive,
                                     OriginAttributes aOriginAttributes);

    [Nested=inside_cpow] async PHal();

    async PHeapSnapshotTempFileHelper();

    async PNecko();

#ifdef MOZ_WEBSPEECH
    async PSpeechSynthesis();
#endif

    async PMedia();

#ifdef MOZ_WEBRTC
    async PWebrtcGlobal();
#endif

    async CreateAudioIPCConnection() returns (FileDescOrError fd);

    sync PURLClassifier(nsIPrincipal principal)
        returns (bool success);

    async PURLClassifierLocal(nsIURI uri, IPCURLClassifierFeature[] features);

    async PLoginReputation(nsIURI formURI);

    async PSessionStorageObserver();

    async PBenchmarkStorage();

    // Services remoting

    async StartVisitedQueries(nsIURI[] uri);
    async SetURITitle(nsIURI uri, nsString title);

    async LoadURIExternal(nsIURI uri,
                          nsIPrincipal triggeringPrincipal,
                          nsIPrincipal redirectPrincipal,
                          MaybeDiscardedBrowsingContext browsingContext,
                          bool wasExternallyTriggered,
                          bool hasValidUserGestureActivation);
    async ExtProtocolChannelConnectParent(uint64_t registrarId);

    // PrefService message
    sync GetGfxVars() returns (GfxVarUpdate[] vars);

    sync SyncMessage(nsString aMessage, ClonedMessageData aData)
      returns (StructuredCloneData[] retval);

    async ShowAlert(nsIAlertNotification alert);

    async CloseAlert(nsString name, bool contextClosed);

    async DisableNotifications(nsIPrincipal principal);

    async OpenNotificationSettings(nsIPrincipal principal);

    async AddSecurityState(MaybeDiscardedWindowContext aContext, uint32_t aStateFlags);

    // Request that the ServiceWorkerManager in the parent process create a
    // notification "click" or "close" event and dispatch it on the relevant
    // ServiceWorker. This needs to happen because when a notification is
    // created it is tied to a specific content process and when the user clicks
    // on the notification, it will be that content process that is notified.
    // However, even if the ServiceWorker lives in that process (it may no
    // longer be in that process, or may have never lived there), the right/only
    // way to talk through the ServiceWorker is through the parent.
    //
    // This happens on PContent because the ServiceWorkerManager lives on the
    // main thread and bouncing this off of PBackground would be silly and
    // complex. In the long run, the notification implementation will be
    // overhauled to directly process the notification click/close and directly
    // translate that to a ServiceWorker event.
    async NotificationEvent(nsString type, NotificationEventData data);

    // Creates a helper for forwarding data from an nsExternalAppHandler
    // running in the content process, to one running in the parent
    // process.
    // Bug 1574372 aims to run nsExternalAppHandler entirely in the
    // parent so that we can remove this.
    //
    // Serializes the uri, loadInfo, contentType, referrer, contentDisposition
    // headers and contentLength of the channel so that we can make them
    // available to the parent instance via a nsIChannel helper. Also
    // passes whether the original channel was an instance of nsIFileChannel.
    //
    // aContext is the BrowsingContext that initiated the load, and created the
    // channel.
    //
    // Pass true for aForceSave to always save this content to disk, regardless of
    // nsIMIMEInfo and other such influences.
    // Pass true for aShouldCloseWindow to specify that aContext was opened specifically
    // for this load, and should be closed once we've handled it.
    async PExternalHelperApp(nsIURI uri,
                             LoadInfoArgs? loadInfoArgs,
                             nsCString aMimeContentType,
                             nsCString aContentDisposition,
                             uint32_t aContentDispositionHint,
                             nsString aContentDispositionFilename,
                             bool aForceSave,
                             int64_t aContentLength,
                             bool aWasFileChannel,
                             nsIURI aReferrer,
                             MaybeDiscardedBrowsingContext aContext,
                             bool aShouldCloseWindow);

    async PHandlerService();

    async AddGeolocationListener(bool highAccuracy);
    async RemoveGeolocationListener();
    async SetGeolocationHigherAccuracy(bool enable);

    async ConsoleMessage(nsString message);
    async ScriptErrorWithStack(nsString message, nsString sourceName, nsString sourceLine,
                               uint32_t lineNumber, uint32_t colNumber, uint32_t flags,
                               nsCString category, bool privateWindow,
                               bool fromChromeContext, ClonedMessageData stack);

    // Places the items within dataTransfer on the clipboard.
    async SetClipboard(IPCDataTransfer aDataTransfer,
                       bool aIsPrivateData,
                       nsIPrincipal aRequestingPrincipal,
                       nsContentPolicyType aContentPolicyType,
                       int32_t aWhichClipboard);

    // Given a list of supported types, returns the clipboard data for the
    // first type that matches.
    sync GetClipboard(nsCString[] aTypes, int32_t aWhichClipboard)
        returns (IPCDataTransfer dataTransfer);

    // Returns a list of formats supported by the clipboard
    sync GetExternalClipboardFormats(int32_t aWhichClipboard, bool aPlainTextOnly) returns (nsCString[] aTypes);

    // Given a list of supported types, returns the clipboard data for the
    // first type that matches.
    async GetClipboardAsync(nsCString[] aTypes, int32_t aWhichClipboard) returns (IPCDataTransferOrError dataTransfer);

    // Clears the clipboard.
    async EmptyClipboard(int32_t aWhichClipboard);

    // Returns true if data of one of the specified types is on the clipboard.
    sync ClipboardHasType(nsCString[] aTypes, int32_t aWhichClipboard)
        returns (bool hasType);

    // Given a list of supported types, returns a list of types that clipboard
    // constains the data for the specified type.
    async ClipboardHasTypesAsync(nsCString [] aTypes, int32_t aWhichClipboard)
        returns (nsCString [] types);

    // 'Play', 'Beep' and 'PlayEventSound' are the only nsISound methods used in
    // the content process.
    [Compress] async PlaySound(nsIURI aURL);
    [Compress] async Beep();
    [Compress] async PlayEventSound(uint32_t aEventId);

    sync GetIconForExtension(nsCString aFileExt, uint32_t aIconSize)
        returns (uint8_t[] bits);

    // Tell the parent that the child has gone idle for the first time.
    async FirstIdle();

    async DeviceReset();

    async CopyFavicon(nsIURI oldURI, nsIURI newURI, bool isPrivate);

    async FindImageText(IPCImage image, nsCString[] languages)
        returns (TextRecognitionResultOrError result);

    /**
     * Notifies the parent about a recording device is starting or shutdown.
     * @param recordingStatus starting or shutdown
     * @param pageURL URL that request that changing the recording status
     * @param isAudio recording start with microphone
     * @param isVideo recording start with camera
     */
    async RecordingDeviceEvents(nsString recordingStatus,
                                nsString pageURL,
                                bool isAudio,
                                bool isVideo);

    // Graphics errors
    async GraphicsError(nsCString aError);

    // Driver crash guards. aGuardType must be a member of CrashGuardType.
    sync BeginDriverCrashGuard(uint32_t aGuardType) returns (bool crashDetected);
    sync EndDriverCrashGuard(uint32_t aGuardType);

    async AddIdleObserver(uint64_t observerId, uint32_t idleTimeInS);
    async RemoveIdleObserver(uint64_t observerId, uint32_t idleTimeInS);

    /**
     * This message is only used on X11 platforms.
     *
     * Send a dup of the plugin process's X socket to the parent
     * process.  In theory, this scheme keeps the plugin's X resources
     * around until after both the plugin process shuts down *and* the
     * parent process closes the dup fd.  This is used to prevent the
     * parent process from crashing on X errors if, e.g., the plugin
     * crashes *just before* a repaint and the parent process tries to
     * use the newly-invalid surface.
     */
    async BackUpXResources(FileDescriptor aXSocketFd);

    async RequestAnonymousTemporaryFile(uint64_t aID);

    /**
     * Notifies the parent that the child needs no more ForceKill dump.
     */
    [Priority=control] async NotifyShutdownSuccess();

    /**
     * Notifies the parent to continue shutting down after the child performs
     * its shutdown tasks.
     */
    async FinishShutdown();

    async UpdateDropEffect(uint32_t aDragAction, uint32_t aDropEffect);

    /**
     * Initiates an asynchronous request for permission for the
     * provided principal.
     *
     * @param aRequests
     *   The array of permissions to request.
     * @param aPrincipal
     *   The principal of the request.
     * @param aTopLevelPrincipal
     *   The principal of the top level page the request comes from.
     * @param tabId
     *   To identify which tab issues this request.
     *
     * NOTE: The principal is untrusted in the parent process. Only
     *       principals that can live in the content process should
     *       provided.
     */
    async PContentPermissionRequest(PermissionRequest[] aRequests,
                                    nsIPrincipal aPrincipal,
                                    nsIPrincipal aTopLevelPrincipal,
                                    bool aIsHandlingUserInput,
                                    bool aMaybeUnsafePermissionDelegate,
                                    TabId tabId);

    /**
     * If the profiler is running when the process shuts down, this sends the
     * profile data collected so far.
     *
     * @param aProfile
     *   This may contain an empty string (unknown issue), an error message
     *   starting with '*', or a profile as a stringified JSON object.
     */
    async ShutdownProfile(nsCString aProfile);

    /**
     * This sends any collected perf stats data on shutdown.
     */
    async ShutdownPerfStats(nsCString aPerfStats);

    /**
     * Request graphics initialization information from the parent.
     */
    sync GetGraphicsDeviceInitData()
        returns (ContentDeviceData aData);

    /**
     * Request a buffer containing the contents of the output color profile.
     * If set, this is the file pointed to by
     * gfx.color_management.display_profile, otherwise it contains a
     * platform-specific default
     */
    sync GetOutputColorProfileData()
        returns (uint8_t[] aOutputColorProfileData);

    /**
     * A shared font list (see gfx/thebes/SharedFontList.*) contains a list
     * of shared-memory blocks that are used to store all the font list data.
     * The font list created in the parent process is the only one that can
     * create or store objects into the shared memory; content processes font
     * lists have read-only access to it.
     *
     * To minimize the cost of record allocations, the shared font list
     * bump-allocates new objects that it adds to the shared memory blocks
     * (i.e. the records stored in the shared memory blocks are only ever
     * appended, and never freed except when the entire font list is
     * reconstructed).
     *
     * When initially created by the parent process, the font list may contain
     * nothing except a header, and the list of the system's installed font
     * family names. Additional data about the families (styled faces available
     * and character coverage) is appended to the font list during the session
     * as a given font is considered for use, because loading all data for all
     * installed fonts during startup is too expensive/slow.
     *
     * During content process launch, a content process's first step in
     * gaining access to the font list is to call GetFontListShmBlock,
     * passing index zero in order to get access to the first block, which
     * contains the font list header and the list of font-family records
     * (which may be virtually all uninitialized at this time, containing
     * nothing but the family names). Once a content process determines a
     * font-family name it wants to use (e.g. from a CSS font-family list, or
     * from preferences), if that Family record has not yet been initialized,
     * it will call InitializeFamily (below) to have the parent process
     * populate Face records in the shared memory with the family's styles.
     * The content process can then pick the face with best style match from
     * the available faces according to the CSS font matching algorithm, load
     * its character map, then send the map to the parent process using
     * SetCharacterMap (so that the parent process can share the map with all
     * processes to avoid duplication of work).
     *
     * At some point, as the parent process adds data to the font list, a new
     * shared-memory block will probably be needed. At that point the parent
     * will create a new block and append it to its share memory block list.
     * The new Block index will start to appear in Pointer records in the
     * shared memory, and the content process's can then fetch those other
     * blocks using this function as needed.
     *
     * @param aGeneration
     *   The font list has a Generation ID stored in its Header, and any time
     *   the parent process needs to reinitialize the list (because of a change
     *   in the available font repertoire) a new Generation ID is assigned.
     *   Content processes pass the Generation of the list they're using in
     *   all messages, so that the parent can recognize if they're out of date
     *   and safely ignore such messages. (When the parent rebuilds the list,
     *   it will notify all content processes, but they may still send a few
     *   messages that relate to the obsolete list before they have processed
     *   this notification.)
     * @param aIndex
     *   (Zero-based) index of the shared-memory block to be mapped.
     *   In a typical case, there will be a handful of blocks altogether, so
     *   each content process only needs to make this request a few times.
     * @returns aHandle
     *   Handle that can be used to construct a SharedMemory that maps the
     *   requested block of memory.
     *   If aGeneration does not match the parent's font list generation ID, or
     *   if requesting a block that does not exist (i.e. with aIndex greater
     *   than or equal to the number of blocks actually in existence), returns
     *   a null handle.
     *
     * This is a sync message because the content process needs font data in
     * order to perform font-matching (e.g. during reflow), and cannot continue
     * until it has mapped the font-list memory.
     */
    sync GetFontListShmBlock(uint32_t aGeneration, uint32_t aIndex)
        returns (SharedMemoryHandle aHandle);

    /**
     * Ask the parent to initialize a given font family, so that face metadata
     * will be available. Content processes will only call this for families
     * where the Face data has not yet been populated, so it will generally be
     * called no more than once per family. (It may not be needed at all, if
     * the parent process has already initialized the families that content
     * wants to use.)
     *
     * @param aGeneration
     *   Font-list generation, so requests relating to an obsolete list can be
     *   ignored (see comments for GetFontListShmBlock).
     * @param aFamilyIndex
     *   The 0-based index of the Family within the font-list that a content
     *   process needs to use.
     * @param aLoadCmaps
     *   If true, the parent should eagerly load character maps for the faces
     *   in the family.
     *
     * This is a sync message because the content process cannot complete its
     * font-matching until the family is fully populated with Face records.
     * If we make it async, content processes will reflow using fallbacks,
     * and then have to reflow again once all the font information needed
     * becomes available.
     */
    sync InitializeFamily(uint32_t aGeneration, uint32_t aFamilyIndex,
                          bool aLoadCmaps);

    /**
     * Record the character map of a given Face in the font list.
     *
     * @param aGeneration
     *   Font-list generation, so requests relating to an obsolete list can be
     *   ignored (see comments for GetFontListShmBlock).
     * @param aFacePtr
     *   Font-list shared-memory "pointer" to the Face record to be updated.
     *   A Pointer is a record of a shared-memory block index and an offset
     *   within that block, which each process that maps the block can convert
     *   into a real pointer in its address space.
     * @param aMap
     *   The character coverage map of the face. (This will be stored as a
     *   SharedBitSet record within the shared font list, and the Face record
     *   will be updated to reference it.)
     */
    async SetCharacterMap(uint32_t aGeneration, Pointer aFacePtr, gfxSparseBitSet aMap);

    /**
     * Ask the parent to set up the merged charmap for a family, to accelerate
     * future fallback searches.
     * aFamilyPtr may refer to an element of either the Families() or AliasFamilies().
     */
    async SetupFamilyCharMap(uint32_t aGeneration, Pointer aFamilyPtr);

    /**
     * Ask the parent to try and complete the InitOtherFamilyNames task, because
     * we're trying to look up a localized font name. This is a sync method so that
     * the update will be available before the child continues reflow; however, it
     * is possible the task will have timed-out in the parent and not actually
     * completed during this call.
     *
     * @param aGeneration
     *   Font-list generation, so requests relating to an obsolete list can be
     *   ignored (see comments for GetFontListShmBlock).
     * @param aDefer
     *   Parameter aDeferOtherFamilyNamesLoading to be passed to
     *   gfxPlatformFontList::InitOtherFamilyNames, to determine whether name
     *   loading should be deferred to a background task or run immediately.
     * @param aLoaded
     *   Returns whether the font name loading process has completed.
     *
     * TODO: This is currently a sync message but can probably be made async,
     * at the cost of an increased chance of some testcases failing because
     * they depend on lazily-loaded font names.
     */
    sync InitOtherFamilyNames(uint32_t aGeneration, bool aDefer) returns (bool aLoaded);

    /**
     * Ask the parent to load all font character maps, as we need to do an
     * exhaustive font-fallback search. This is done asynchronously; when it
     * finishes, the parent will trigger global reflow so that font selection
     * is re-done in all content, making use of the newly-loaded cmaps.
     * Normally this will only happen once per browser session (unless the
     * font list is rebuilt due to installation/removal of system fonts).
     *
     * @param aGeneration
     *   Font-list generation, so requests relating to an obsolete list can be
     *   ignored (see comments for GetFontListShmBlock).
     * @param aStartIndex
     *   The family index to start from; the sender has determined that cmaps
     *   up to this point are already loaded.
     */
    async StartCmapLoading(uint32_t aGeneration, uint32_t aStartIndex);

    /**
     * Ask the parent for a specific hyphenation resource (identified by URI)
     * as a shared memory block.
     *
     * This is a sync method because at the point where a content process finds
     * that it requires a particular hyphenation dictionary, this is blocking
     * reflow; making it async would require scheduling another reflow after
     * the resource is available, and a possible layout "jump" as line-breaks
     * change. Note that the content process retains a reference to each such
     * resource it requests, so it will only make this call once per locale for
     * which hyphenation data exists.
     *
     * @param aURI
     *   The URI (which currently must always point to an omnijar resource)
     *   for the required hyphenation dictionary.
     * @param aHandle
     *   Returns the shmem handle to the resource (or an invalid shmem handle
     *   in case of failure).
     * @param aLoaded
     *   Returns the size in bytes of the resource.
     */
    sync GetHyphDict(nsIURI aURI) returns (SharedMemoryHandle aHandle, uint32_t aSize);

    async CreateWindow(PBrowser aThisTab,
                       MaybeDiscardedBrowsingContext aParent,
                       PBrowser aNewTab,
                       uint32_t aChromeFlags,
                       bool aCalledFromJS,
                       bool aForPrinting,
                       bool aForWindowDotPrint,
                       nsIURI aURIToLoad,
                       nsCString aFeatures,
                       nsIPrincipal aTriggeringPrincipal,
                       nsIContentSecurityPolicy aCsp,
                       nsIReferrerInfo aReferrerInfo,
                       OriginAttributes aOriginAttributes)
        returns (CreatedWindowInfo window);

    async CreateWindowInDifferentProcess(
      PBrowser aThisTab,
      MaybeDiscardedBrowsingContext aParent,
      uint32_t aChromeFlags,
      bool aCalledFromJS,
      nsIURI aURIToLoad,
      nsCString aFeatures,
      nsString aName,
      nsIPrincipal aTriggeringPrincipal,
      nsIContentSecurityPolicy aCsp,
      nsIReferrerInfo aReferrerInfo,
      OriginAttributes aOriginAttributes);

    sync RemovePermission(nsIPrincipal principal, nsCString permissionType) returns (nsresult rv);

    /**
     * Tell the parent that a decoder's' benchmark has been completed.
     * The result can then be stored in permanent storage.
     */
    async NotifyBenchmarkResult(nsString aCodecName, uint32_t aDecodeFPS);

    /**
     * Notify `push-message` observers without data in the parent.
     */
    async NotifyPushObservers(nsCString scope, nsIPrincipal principal,
                              nsString messageId);

    /**
     * Notify `push-message` observers with data in the parent.
     */
    async NotifyPushObserversWithData(nsCString scope, nsIPrincipal principal,
                                      nsString messageId, uint8_t[] data);

    /**
     * Notify `push-subscription-change` observers in the parent.
     */
    async NotifyPushSubscriptionChangeObservers(nsCString scope,
                                                nsIPrincipal principal);

     async GetFilesRequest(nsID aID, nsString aDirectory, bool aRecursiveFlag);
     async DeleteGetFilesRequest(nsID aID);

     async StoreAndBroadcastBlobURLRegistration(nsCString url, IPCBlob blob,
                                                nsIPrincipal principal,
                                                nsID? aAgentClusterId);

     async UnstoreAndBroadcastBlobURLUnregistration(nsCString url, nsIPrincipal principal);

    /**
     * Messages for communicating child Glean data to the parent process
     */
    async RecordPageLoadEvent(PageLoadExtra event);

    /**
     * Messages for communicating child Telemetry to the parent process
     */
    async AccumulateChildHistograms(HistogramAccumulation[] accumulations);
    async AccumulateChildKeyedHistograms(KeyedHistogramAccumulation[] accumulations);
    async UpdateChildScalars(ScalarAction[] updates);
    async UpdateChildKeyedScalars(KeyedScalarAction[] updates);
    async RecordChildEvents(ChildEventData[] events);
    async RecordDiscardedData(DiscardedData data);

    sync GetA11yContentId() returns (uint32_t aContentId);
    async A11yHandlerControl(uint32_t aPid,
                             IHandlerControlHolder aHandlerControl);

    async AddMemoryReport(MemoryReport aReport);

    async BHRThreadHang(HangDetails aHangDetails);

    async AddPerformanceMetrics(nsID aID, PerformanceInfo[] aMetrics);

    /*
     * Adds a certificate exception for the given hostname and port.
     */
    async AddCertException(nsIX509Cert aCert, nsCString aHostName,
                           int32_t aPort, OriginAttributes aOriginAttributes,
                           bool aIsTemporary)
          returns (nsresult success);

    /*
     * Determines whether storage access can be granted automatically by the
     * storage access API without showing a user prompt.
     */
    async AutomaticStorageAccessPermissionCanBeGranted(nsIPrincipal aPrincipal)
          returns (bool success);

    /*
     * A 3rd party tracking origin (aTrackingOrigin) has received the permission
     * granted to have access to aGrantedOrigin when loaded by aParentWindowId.
     */
    async StorageAccessPermissionGrantedForOrigin(uint64_t aTopLevelWindowId,
                                                  MaybeDiscardedBrowsingContext aParentContext,
                                                  nsIPrincipal aTrackingPrincipal,
                                                  nsCString aTrackingOrigin,
                                                  int aAllowMode,
                                                  StorageAccessPermissionGrantedReason? aReason)
          returns (bool unused);

    async CompleteAllowAccessFor(MaybeDiscardedBrowsingContext aParentContext,
                                 uint64_t aTopLevelWindowId,
                                 nsIPrincipal aTrackingPrincipal,
                                 nsCString aTrackingOrigin,
                                 uint32_t aCookieBehavior,
                                 StorageAccessPermissionGrantedReason aReason)
          returns (StorageAccessPromptChoices? choice);

    async SetAllowStorageAccessRequestFlag(
                                 nsIPrincipal aEmbeddingPrincipal,
                                 nsIURI aEmbeddedOrigin)
          returns (bool success);

    async TestAllowStorageAccessRequestFlag(
                                 nsIPrincipal aEmbeddedPrincipal,
                                 nsIURI aEmbeddingOrigin)
          returns (bool success);

    async StoreUserInteractionAsPermission(nsIPrincipal aPrincipal);

    async TestCookiePermissionDecided(MaybeDiscardedBrowsingContext aContext,
                         nsIPrincipal aPrincipal)
          returns (bool? allowed);

    async TestStorageAccessPermission(nsIPrincipal aEmbeddingPrincipal,
                         nsCString aEmbeddedOrigin)
          returns (bool? allowed);

   /**
    * When media element's controlled state changed in the content process, we
    * have to notify the chrome process in order to update the status of the
    * corresponding media controller, which is used to control all media in the
    * certain tab. We would use the browsing context to find the corresponding
    * controller.
    */
    async NotifyMediaPlaybackChanged(MaybeDiscardedBrowsingContext aContext,
                                     MediaPlaybackState aState);

   /**
    * When media became audible or inaudible in content process, we have to
    * notify chrome process in order to which tab is audible.
    */
    async NotifyMediaAudibleChanged(MaybeDiscardedBrowsingContext aContext,
                                    MediaAudibleState aState);

   /**
    * When media enabled or disabled the Picture-in-Picture mode, we have to
    * update that to the media controller in the chrome process.
    */
    async NotifyPictureInPictureModeChanged(
        MaybeDiscardedBrowsingContext aContext, bool aEnabled);

   /**
    * This method is used to update media session's status when it's being
    * created or destroyed.
    */
    async NotifyMediaSessionUpdated(MaybeDiscardedBrowsingContext aContext, bool aIsCreated);

    /**
     * This method is used to update media session's media metadata whenever its
     * metadata is being updated.
     */
    async NotifyUpdateMediaMetadata(MaybeDiscardedBrowsingContext aContext,
                                    MediaMetadataBase? aMetadata);

    /**
     * This method is used to update media session's playback state whenever its
     * playback state is changed.
     */
    async NotifyMediaSessionPlaybackStateChanged(
        MaybeDiscardedBrowsingContext aContext,
        MediaSessionPlaybackState aMetadata);

    /**
     * This method is used to update media session's supported media session
     * action when the action becomes supported or unsupported.
     */
    async NotifyMediaSessionSupportedActionChanged(
        MaybeDiscardedBrowsingContext aContext,
        MediaSessionAction aAction,
        bool aEnabled);

    /**
     * This method is used to notify the media controller in chrome process that
     * the media element in the browsing context entered fullscreen.
     */
    async NotifyMediaFullScreenState(
        MaybeDiscardedBrowsingContext aContext,
        bool aIsInFullScreen);

    /**
     * This method is used to update media session's position state whenever its
     * position state is being updated.
     */
    async NotifyPositionStateChanged(
        MaybeDiscardedBrowsingContext aContext,
        PositionState aState);

    /**
     * This method will make canonical browsing context to update the count of
     * callers which want to keep the page from being suspended even if the page
     * is inactive.
     */
    async AddOrRemovePageAwakeRequest(MaybeDiscardedBrowsingContext aContext,
                                      bool aShouldAddCount);

#if defined(XP_WIN)
    /**
     * Due to sandboxing, a child process's UntrustedModulesProcessor cannot
     * obtain enough information about a DLL file to determine its
     * trustworthiness. This API asks the chrome process to perform that
     * evaluation.
     */
    async GetModulesTrust(ModulePaths aModPaths, bool aRunAtNormalPriority)
        returns (ModulesMapResult? modMapResult);
#endif  // defined(XP_WIN)

    /**
     * Used to route shutdown diagnostic info from the content process
     * ServiceWorkers to the parent process' ServiceWorkerManager's
     * ServiceWorkerShutdownBlocker. (The only other actor chain available
     * for this would be very convoluted and create ordering problems).
     */
    async ReportServiceWorkerShutdownProgress(uint32_t aShutdownStateId,
                                              Progress aProgress);

    /**
     * Whenever a document is updating the OrientationLock, we need to
     * reject the orientationPendingPromises in other processes.
     */
    async AbortOtherOrientationPendingPromises(MaybeDiscardedBrowsingContext aContext);

    async HistoryReload(MaybeDiscardedBrowsingContext aContext, uint32_t aReloadFlags);

    async NotifyOnHistoryReload(MaybeDiscardedBrowsingContext aContext,
                                bool aForceReload)
            returns (bool canReload, nsDocShellLoadState? loadState,
                     bool? reloadActiveEntry);

    async HistoryCommit(MaybeDiscardedBrowsingContext aContext,
                        uint64_t aLoadID, nsID aChangeID, uint32_t aLoadType,
                        bool aPersist, bool aCloneEntryChildren,
                        bool aChannelExpired, uint32_t aCacheKey);

    async HistoryGo(MaybeDiscardedBrowsingContext aContext, int32_t aOffset,
                    uint64_t aHistoryEpoch, bool aRequireUserInteraction,
                    bool aUserActivation) returns(int32_t? requestedIndex);

    async BlobURLDataRequest(nsCString aBlobURL,
                             nsIPrincipal aTriggeringPrincipal,
                             nsIPrincipal aLoadingPrincipal,
                             OriginAttributes aOriginAttributes,
                             uint64_t aInnerWindowId,
                             nsID? aAgentClusterId)
      returns (BlobURLDataRequestResult aResult);

    async SetActiveSessionHistoryEntry(MaybeDiscardedBrowsingContext context,
                                       nsPoint? previousScrollPosition,
                                       SessionHistoryInfo info, uint32_t loadType,
                                       uint32_t updatedCacheKey, nsID changeID);
    async ReplaceActiveSessionHistoryEntry(
        MaybeDiscardedBrowsingContext context, SessionHistoryInfo info);

    async RemoveDynEntriesFromActiveSessionHistoryEntry(
        MaybeDiscardedBrowsingContext aContext);

    async RemoveFromSessionHistory(
        MaybeDiscardedBrowsingContext aContext, nsID changeID);

    // Called when a nsDocShellLoadState which was received over IPC is
    // destroyed in the content process to clean up pending state left behind
    // tracking the load state in the parent process.
    [LazySend] async CleanupPendingLoadState(uint64_t aLoadIdentifier);

both:
    async ScriptError(nsString message, nsString sourceName, nsString sourceLine,
                      uint32_t lineNumber, uint32_t colNumber, uint32_t flags,
                      nsCString category, bool privateWindow, uint64_t innerWindowId,
                      bool fromChromeContext);

    /**
     * Used in fission to report timing data when the parent window is in
     * another process. Child frame will send data to its ContentParent which
     * will then identify the ContentParent for the innerWindowId and pass
     * the data to the correct process.
     * loadInfo is passed in order to enforce same-origin security checks
     * aData must be non-null.
     */
    async ReportFrameTimingData(LoadInfoArgs? loadInfo, nsString entryName,
                                nsString initiatorType,
                                UniquePtr<PerformanceTimingData> aData);

    async CommitBrowsingContextTransaction(MaybeDiscardedBrowsingContext aContext,
                                           BrowsingContextTransaction aTransaction,
                                           uint64_t aEpoch);

    async AsyncMessage(nsString aMessage, ClonedMessageData aData);

    /**
     * Notify `push-subscription-modified` observers in the parent and child.
     */
    async NotifyPushSubscriptionModifiedObservers(nsCString scope,
                                                  nsIPrincipal principal);

    /**
     * Send a Push error message to all service worker clients in the parent or
     * child.
     */
    async PushError(nsCString scope, nsIPrincipal principal, nsString message,
                    uint32_t flags);

    /**
     * Creates a new BrowsingContext, initialized with the values provided in
     * `BrowsingContextInitializer`.
     *
     * This message may only be sent to the parent in limited situations. If the
     * new BrowsingContext has a parent window, it must be owned by the
     * embedding process, otherwise it must be owned by the opener, if set.
     */
    [LazySend] async CreateBrowsingContext(uint64_t aGroupId, BrowsingContextInitializer aInit);

    /**
     * If aDoDiscard is true, discards the passed-in BrowsingContext. If the
     * BrowsingContext has already been discarded, this message does nothing.
     * If the receiver is the parent process, resolves when all content
     * processes have flagged the BrowsingContext as discarded, and if the
     * receiver is a child process, resolves when that child process has flagged
     * the BrowsingContext as discarded.
     */
    async DiscardBrowsingContext(MaybeDiscardedBrowsingContext aContext, bool aDoDiscard)
            returns (uint64_t unused);

    async AdjustWindowFocus(MaybeDiscardedBrowsingContext aContext,
                            bool aIsVisible, uint64_t aActionId);
    async WindowClose(MaybeDiscardedBrowsingContext aContext,
                      bool aTrustedCaller);
    async WindowFocus(MaybeDiscardedBrowsingContext aContext,
                      CallerType aCallerType, uint64_t aActionId);
    async WindowBlur(MaybeDiscardedBrowsingContext aContext,
                     CallerType aCallerType);
    async RaiseWindow(MaybeDiscardedBrowsingContext aContext, CallerType aCallerType, uint64_t aActionId);
    async ClearFocus(MaybeDiscardedBrowsingContext aContext);
    async SetFocusedBrowsingContext(MaybeDiscardedBrowsingContext aContext, uint64_t aActionId);
    async SetActiveBrowsingContext(MaybeDiscardedBrowsingContext aContext, uint64_t aActionId);
    async UnsetActiveBrowsingContext(MaybeDiscardedBrowsingContext aContext, uint64_t aActionId);
    async SetFocusedElement(MaybeDiscardedBrowsingContext aContext, bool aNeedsFocus);
    async FinalizeFocusOuter(MaybeDiscardedBrowsingContext aContext, bool aCanFocus,
                             CallerType aCallerType);
parent:
    [LazySend] async InsertNewFocusActionId(uint64_t aActionId);
    async BlurToParent(MaybeDiscardedBrowsingContext aFocusedBrowsingContext,
                      MaybeDiscardedBrowsingContext aBrowsingContextToClear,
                      MaybeDiscardedBrowsingContext aAncestorBrowsingContextToFocus,
                      bool aIsLeavingDocument, bool aAdjustWidget,
                      bool aBrowsingContextToClearHandled,
                      bool aAncestorBrowsingContextToFocusHandled, uint64_t aActionId);
child:
    async BlurToChild(MaybeDiscardedBrowsingContext aFocusedBrowsingContext,
                      MaybeDiscardedBrowsingContext aBrowsingContextToClear,
                      MaybeDiscardedBrowsingContext aAncestorBrowsingContextToFocus,
                      bool aIsLeavingDocument, bool aAdjustWidget, uint64_t aActionId);
    async SetupFocusedAndActive(MaybeDiscardedBrowsingContext aFocusedBrowsingContext,
                                uint64_t aActionIdForFocused,
                                MaybeDiscardedBrowsingContext aActiveBrowsingContext,
                                uint64_t aActionId);
    async ReviseActiveBrowsingContext(uint64_t aOldActionId,
                                      MaybeDiscardedBrowsingContext aActiveBrowsingContext,
                                      uint64_t aNewActionId);
    async ReviseFocusedBrowsingContext(uint64_t aOldActionId,
                                       MaybeDiscardedBrowsingContext aFocusedBrowsingContext,
                                       uint64_t aNewActionId);
both:
    async MaybeExitFullscreen(MaybeDiscardedBrowsingContext aContext);
    async WindowPostMessage(MaybeDiscardedBrowsingContext aContext,
                            ClonedOrErrorMessageData aMessage,
                            PostMessageData aData);

    async CommitWindowContextTransaction(MaybeDiscardedWindowContext aContext,
                                         WindowContextTransaction aTransaction,
                                         uint64_t aEpoch);

child:
    // NOTE: These methods are only needed on the child, as the parent
    // WindowContext is managed using the PWindowGlobal actor's lifecycle.
    [LazySend] async CreateWindowContext(WindowContextInitializer aInit);
    async DiscardWindowContext(uint64_t aContextId) returns (bool unused);

parent:
    // Temporary (bug 1641989) conduit for Glean data in content processes.
    // Sent from time-to-time to limit the amount of data vulnerable to loss.
    // Buffer contains bincoded Rust structs.
    async FOGData(ByteBuf buf);

child:
    // Temporary (bug 1641989) conduit for Glean data in content processes.
    // Tells the child to flush any pending data. Used in tests and ping
    // assembly. Buffer contains bincoded Rust structs.
    async FlushFOGData() returns (ByteBuf buf);

parent:
    async SetContainerFeaturePolicy(MaybeDiscardedBrowsingContext aContainerContext,
                                    FeaturePolicy aContainerFeaturePolicy);

    // Obtain an icon from the system widget toolkit, in nsIconDecoder
    // format.  Not supported (or needed) on all platforms; see the
    // implementation in ContentParent::RecvGetSystemIcon for details.
    async GetSystemIcon(nsIURI aURI) returns (nsresult aResult, ByteBuf? aData);

#ifdef FUZZING_SNAPSHOT
    // Used by the child process to signal that it is ready to start fuzzing.
    // This can in particular be used to wait for a particular event in a
    // test document before taking the snapshot and starting e.g. IPC fuzzing.
    async SignalFuzzingReady();
#endif
};

}
}