author Markus Stange <>
Fri, 15 Oct 2021 16:52:33 +0000
changeset 596026 ff6d6594f7b046db57fa377eee3e8760a3ff4751
parent 595679 5121dded09731b37ccc5ea73383041a9afac3ee6
permissions -rw-r--r--
Bug 1736049 - Stop calling `[[NSCursor currentCursor] set]` on every mouse move. r=emilio This was only necessary when we had binary plug-ins overriding the cursor from under us. We no longer support plug-ins. Calling -[NSCursor set] has a performance cost on macOS Monterey when cursor accessibility coloring is enabled, so we want to avoid calling it unnecessarily. It also leaks memory in the current Monterey Beta (see bug 1735345), so calling it less often will leak less memory. I have checked the testcases of bug 496601 and of bug 1423275, they still work as expected with this fix. Differential Revision:

/* -*- Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 8 -*- */
/* vim: set sw=4 ts=8 et tw=80 ft=cpp : */
/* 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 */

include protocol PBackground;
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 PFileDescriptorSet;
include protocol PHal;
include protocol PHeapSnapshotTempFileHelper;
include protocol PProcessHangMonitor;
include protocol PImageBridge;
include protocol PRemoteLazyInputStream;
include protocol PLoginReputation;
include protocol PMedia;
include protocol PNecko;
include protocol PStreamFilter;
include protocol PGMPContent;
include protocol PGMPService;
include protocol PGMP;
include protocol PPrinting;
include protocol PChildToParentStream;
include protocol PParentToChildStream;
include protocol PSpeechSynthesis;
include protocol PTestShell;
include protocol PRemoteSpellcheckEngine;
include protocol PWebBrowserPersistDocument;
include protocol PWebrtcGlobal;
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;

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/ReferrerInfoUtils.h";
include "mozilla/ipc/ByteBufUtils.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 class IPC::Principal from "mozilla/dom/PermissionMessageUtils.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::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::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::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";
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";
[RefCounted] using class nsDocShellLoadState from "nsDocShellLoadState.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::ContentBlocking::StorageAccessPromptChoices from "mozilla/ContentBlocking.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::PDMFactory::MediaCodecsSupported from "PDMFactory.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";

union ChromeRegistryItem

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;
// 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;

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

struct SystemFontList {
    SystemFontListEntry[] entries;
    SystemFontOptions options;

union SystemParameterValue {

struct SystemParameterKVPair {
  uint8_t id;
  SystemParameterValue value;

struct ClipboardCapabilities {
  bool supportsSelectionClipboard;
  bool supportsFindClipboard;

union FileDescOrError {

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

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;

  // 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;
    // 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;
    SystemParameterKVPair[] systemParameters;

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
// ( 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

union BlobURLDataRequestResult

 * 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.
[NestedUpTo=inside_cpow] sync protocol PContent
    manages PBrowser;
    manages PContentPermissionRequest;
    manages PCycleCollectWithLogs;
    manages PExtensions;
    manages PExternalHelperApp;
    manages PFileDescriptorSet;
    manages PHal;
    manages PHandlerService;
    manages PHeapSnapshotTempFileHelper;
    manages PRemoteLazyInputStream;
    manages PMedia;
    manages PNecko;
    manages PPrinting;
    manages PChildToParentStream;
    manages PParentToChildStream;
    manages PSpeechSynthesis;
    manages PTestShell;
    manages PRemoteSpellcheckEngine;
    manages PWebBrowserPersistDocument;
    manages PWebrtcGlobal;
    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, 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!
    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();

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

    async PFileDescriptorSet(FileDescriptor fd);

    // 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);

    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);

    // 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);
#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 UpdateSystemParameters(SystemParameterKVPair[] aUpdates);

    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);

    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);

     * 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);

    // 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);

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

     * 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, Principal principal, nsString messageId);

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

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

    async GetFilesResponse(nsID aID, GetFilesResponseResult aResult);

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

    async BlobURLUnregistration(nsCString aURI);

    async GMPsChanged(GMPCapabilityData[] capabilities);

    async PParentToChildStream();

    async ProvideAnonymousTemporaryFile(uint64_t aID, FileDescOrError aFD);

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

    async RefreshScreens(ScreenDetails[] aScreens);

    async PRemoteLazyInputStream(nsID aID, uint64_t aSize);

    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);

    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 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);

  async CanSavePresentation(MaybeDiscardedBrowsingContext aTopLevelContext,
      uint64_t? aDocumentChannelId) returns (bool success);

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

  async FlushTabState(MaybeDiscardedBrowsingContext aBrowsingContext)
      returns(bool aHadContext);

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

    async RemoveFromBFCache(MaybeDiscardedBrowsingContext aContext);

    async InitBackground(Endpoint<PBackgroundParent> aEndpoint);

    async CreateGMPService();

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

    async PRemoteSpellcheckEngine();

    async InitCrashReporter(NativeThreadId tid);

    sync IsSecureURI(nsIURI aURI, uint32_t aFlags,
                     OriginAttributes aOriginAttributes)
        returns (bool isSecureURI);

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

    [Nested=inside_cpow] async PHal();

    async PHeapSnapshotTempFileHelper();

    async PNecko();

    async PPrinting();

    async PChildToParentStream();

    async PSpeechSynthesis();

    async PMedia();

    async PWebrtcGlobal();

    async CreateAudioIPCConnection() returns (FileDescOrError fd);

    sync PURLClassifier(Principal 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,
                          MaybeDiscardedBrowsingContext browsingContext,
                          bool wasExternallyTriggered);
    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);

    async DisableNotifications(Principal principal);

    async OpenNotificationSettings(Principal 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,
                       Principal 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);

    // 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);

    // '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);

     * 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);

     * Sets "offline-app" permission for the principal.  Called when we hit
     * a web app with the manifest attribute in <html>
    async SetOfflinePermission(Principal principal);

     * 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,
                                    Principal aPrincipal,
                                    Principal aTopLevelPrincipal,
                                    bool aIsHandlingUserInput,
                                    bool aMaybeUnsafePermissionDelegate,
                                    TabId tabId);

    async ShutdownProfile(nsCString aProfile);

     * 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 aWidthSpecified,
                       bool aForPrinting,
                       bool aForWindowDotPrint,
                       nsIURI aURIToLoad,
                       nsCString aFeatures,
                       float aFullZoom,
                       Principal aTriggeringPrincipal,
                       nsIContentSecurityPolicy aCsp,
                       nsIReferrerInfo aReferrerInfo,
                       OriginAttributes aOriginAttributes)
        returns (CreatedWindowInfo window);

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

     * Tells the parent to ungrab the pointer on the default display.
     * This is for GTK platforms where we have to ensure the pointer ungrab happens in the
     * chrome process as that's the process that receives the pointer event.
    sync UngrabPointer(uint32_t time);

    sync RemovePermission(Principal 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, Principal principal,
                              nsString messageId);

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

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

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

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

     async UnstoreAndBroadcastBlobURLUnregistration(nsCString url, Principal principal);

     * 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(nsCString aSerializedCert, uint32_t aFlags,
                           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(Principal 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,
                                                  Principal aTrackingPrincipal,
                                                  nsCString aTrackingOrigin,
                                                  int aAllowMode,
                                                  StorageAccessPermissionGrantedReason? aReason)
          returns (bool unused);

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

    async StoreUserInteractionAsPermission(Principal aPrincipal);

    async AsyncShouldAllowAccessFor(MaybeDiscardedBrowsingContext aContext,
                                    Principal aPrincipal)
          returns (bool allowed, uint32_t rejectReason);

    * 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);

    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);

    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.
     * aData must be non-null.
    async ReportFrameTimingData(uint64_t innerWindowId, 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,
                                                  Principal principal);

     * Send a Push error message to all service worker clients in the parent or
     * child.
    async PushError(nsCString scope, Principal 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.
    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);
    async InsertNewFocusActionId(uint64_t aActionId);
    async BlurToParent(MaybeDiscardedBrowsingContext aFocusedBrowsingContext,
                      MaybeDiscardedBrowsingContext aBrowsingContextToClear,
                      MaybeDiscardedBrowsingContext aAncestorBrowsingContextToFocus,
                      bool aIsLeavingDocument, bool aAdjustWidget,
                      bool aBrowsingContextToClearHandled,
                      bool aAncestorBrowsingContextToFocusHandled, uint64_t aActionId);
    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);
    async MaybeExitFullscreen(MaybeDiscardedBrowsingContext aContext);
    async WindowPostMessage(MaybeDiscardedBrowsingContext aContext,
                            ClonedOrErrorMessageData aMessage,
                            PostMessageData aData);

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

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

    // 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);

    // 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);

    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);