Adding upstream version 115.7.0esr.upstream/115.7.0esr

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

1 files changed, 3680 insertions, 0 deletions

diff --git a/dom/base/nsContentUtils.h b/dom/base/nsContentUtils.h
new file mode 100644
index 0000000000..79c2e9c4b1
--- /dev/null
+++ b/dom/base/nsContentUtils.h
@@ -0,0 +1,3680 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=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/. */
+
+/* A namespace class for static content utilities. */
+
+#ifndef nsContentUtils_h___
+#define nsContentUtils_h___
+
+#if defined(XP_WIN)
+#  include <float.h>
+#endif
+
+#if defined(SOLARIS)
+#  include <ieeefp.h>
+#endif
+
+#include <cstddef>
+#include <cstdint>
+#include <functional>
+#include <tuple>
+#include <utility>
+#include "ErrorList.h"
+#include "Units.h"
+#include "js/Id.h"
+#include "js/RootingAPI.h"
+#include "mozilla/AlreadyAddRefed.h"
+#include "mozilla/Assertions.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/BasicEvents.h"
+#include "mozilla/CORSMode.h"
+#include "mozilla/CallState.h"
+#include "mozilla/Maybe.h"
+#include "mozilla/RefPtr.h"
+#include "mozilla/TaskCategory.h"
+#include "mozilla/TimeStamp.h"
+#include "mozilla/UniquePtr.h"
+#include "mozilla/dom/BindingDeclarations.h"
+#include "mozilla/dom/FromParser.h"
+#include "mozilla/fallible.h"
+#include "mozilla/gfx/Point.h"
+#include "nsCOMPtr.h"
+#include "nsHashtablesFwd.h"
+#include "nsIContentPolicy.h"
+#include "nsINode.h"
+#include "nsIScriptError.h"
+#include "nsIThread.h"
+#include "nsLiteralString.h"
+#include "nsMargin.h"
+#include "nsPIDOMWindow.h"
+#include "nsRFPService.h"
+#include "nsStringFwd.h"
+#include "nsTArray.h"
+#include "nsTLiteralString.h"
+#include "prtime.h"
+
+#if defined(XP_WIN)
+// Undefine LoadImage to prevent naming conflict with Windows.
+#  undef LoadImage
+#endif
+
+class JSObject;
+class imgICache;
+class imgIContainer;
+class imgINotificationObserver;
+class imgIRequest;
+class imgLoader;
+class imgRequestProxy;
+class nsAtom;
+class nsAttrValue;
+class nsAutoScriptBlockerSuppressNodeRemoved;
+class nsContentList;
+class nsCycleCollectionTraversalCallback;
+class nsDocShell;
+class nsGlobalWindowInner;
+class nsHtml5StringParser;
+class nsIArray;
+class nsIBidiKeyboard;
+class nsIChannel;
+class nsIConsoleService;
+class nsIContent;
+class nsIDocShell;
+class nsIDocShellTreeItem;
+class nsIDocumentLoaderFactory;
+class nsIDragSession;
+class nsIFile;
+class nsIFragmentContentSink;
+class nsIFrame;
+class nsIHttpChannel;
+class nsIIOService;
+class nsIImageLoadingContent;
+class nsIInterfaceRequestor;
+class nsILoadGroup;
+class nsILoadInfo;
+class nsIObserver;
+class nsIPluginTag;
+class nsIPrincipal;
+class nsIReferrerInfo;
+class nsIRequest;
+class nsIRunnable;
+class nsIScreen;
+class nsIScriptContext;
+class nsIScriptSecurityManager;
+class nsISerialEventTarget;
+class nsIStringBundle;
+class nsIStringBundleService;
+class nsISupports;
+class nsITransferable;
+class nsIURI;
+class nsIWidget;
+class nsIWritableVariant;
+class nsIXPConnect;
+class nsNodeInfoManager;
+class nsParser;
+class nsPIWindowRoot;
+class nsPresContext;
+class nsStringBuffer;
+class nsStringHashKey;
+class nsTextFragment;
+class nsView;
+class nsWrapperCache;
+
+struct JSContext;
+struct nsPoint;
+
+template <class T>
+class nsRefPtrHashKey;
+
+namespace IPC {
+class Message;
+class MessageReader;
+class MessageWriter;
+}  // namespace IPC
+
+namespace JS {
+class Value;
+class PropertyDescriptor;
+}  // namespace JS
+
+namespace mozilla {
+class Dispatcher;
+class EditorBase;
+class ErrorResult;
+class EventListenerManager;
+class HTMLEditor;
+class LazyLogModule;
+class LogModule;
+class PresShell;
+class TextEditor;
+class WidgetDragEvent;
+class WidgetKeyboardEvent;
+
+struct InputEventOptions;
+
+template <typename ParentType, typename RefType>
+class RangeBoundaryBase;
+
+template <typename T>
+class NotNull;
+template <class T>
+class StaticRefPtr;
+
+namespace dom {
+class IPCImage;
+struct AutocompleteInfo;
+class BrowserChild;
+class BrowserParent;
+class BrowsingContext;
+class BrowsingContextGroup;
+class ContentChild;
+class ContentFrameMessageManager;
+class ContentParent;
+struct CustomElementDefinition;
+class CustomElementRegistry;
+class DataTransfer;
+class Document;
+class DocumentFragment;
+class DOMArena;
+class Element;
+class Event;
+class EventTarget;
+class HTMLInputElement;
+class IPCTransferable;
+class IPCTransferableData;
+class IPCTransferableDataImageContainer;
+class IPCTransferableDataItem;
+struct LifecycleCallbackArgs;
+class MessageBroadcaster;
+class NodeInfo;
+class Selection;
+struct StructuredSerializeOptions;
+class WorkerPrivate;
+enum class ElementCallbackType;
+enum class ReferrerPolicy : uint8_t;
+}  // namespace dom
+
+namespace ipc {
+class BigBuffer;
+class IProtocol;
+}  // namespace ipc
+
+namespace gfx {
+class DataSourceSurface;
+enum class SurfaceFormat : int8_t;
+}  // namespace gfx
+
+class WindowRenderer;
+
+}  // namespace mozilla
+
+extern const char kLoadAsData[];
+
+// Stolen from nsReadableUtils, but that's OK, since we can declare the same
+// name multiple times.
+const nsString& EmptyString();
+const nsCString& EmptyCString();
+
+enum EventNameType {
+  EventNameType_None = 0x0000,
+  EventNameType_HTML = 0x0001,
+  EventNameType_XUL = 0x0002,
+  EventNameType_SVGGraphic = 0x0004,  // svg graphic elements
+  EventNameType_SVGSVG = 0x0008,      // the svg element
+  EventNameType_SMIL = 0x0010,        // smil elements
+  EventNameType_HTMLBodyOrFramesetOnly = 0x0020,
+  EventNameType_HTMLMarqueeOnly = 0x0040,
+
+  EventNameType_HTMLXUL = 0x0003,
+  EventNameType_All = 0xFFFF
+};
+
+struct EventNameMapping {
+  // This holds pointers to nsGkAtoms members, and is therefore safe as a
+  // non-owning reference.
+  nsAtom* MOZ_NON_OWNING_REF mAtom;
+  int32_t mType;
+  mozilla::EventMessage mMessage;
+  mozilla::EventClassID mEventClassID;
+  // True if mAtom is possibly used by special SVG/SMIL events, but
+  // mMessage is eUnidentifiedEvent. See EventNameList.h
+  bool mMaybeSpecialSVGorSMILEvent;
+};
+
+namespace mozilla {
+enum class PreventDefaultResult : uint8_t { No, ByContent, ByChrome };
+
+namespace dom {
+enum JSONBehavior { UndefinedIsNullStringLiteral, UndefinedIsVoidString };
+}
+}  // namespace mozilla
+
+class nsContentUtils {
+  friend class nsAutoScriptBlockerSuppressNodeRemoved;
+  using Element = mozilla::dom::Element;
+  using Document = mozilla::dom::Document;
+  using Cancelable = mozilla::Cancelable;
+  using CanBubble = mozilla::CanBubble;
+  using Composed = mozilla::Composed;
+  using ChromeOnlyDispatch = mozilla::ChromeOnlyDispatch;
+  using EventMessage = mozilla::EventMessage;
+  using TimeDuration = mozilla::TimeDuration;
+  using Trusted = mozilla::Trusted;
+  using JSONBehavior = mozilla::dom::JSONBehavior;
+  using RFPTarget = mozilla::RFPTarget;
+
+ public:
+  static nsresult Init();
+
+  static bool IsCallerChrome();
+  static bool ThreadsafeIsCallerChrome();
+  static bool IsCallerUAWidget();
+  static bool IsFuzzingEnabled()
+#ifndef FUZZING
+  {
+    return false;
+  }
+#else
+      ;
+#endif
+  static bool IsErrorPage(nsIURI* aURI);
+
+  static bool IsCallerChromeOrFuzzingEnabled(JSContext* aCx, JSObject*) {
+    return ThreadsafeIsSystemCaller(aCx) || IsFuzzingEnabled();
+  }
+
+  static bool IsCallerChromeOrElementTransformGettersEnabled(JSContext* aCx,
+                                                             JSObject*);
+
+  // The APIs for checking whether the caller is system (in the sense of system
+  // principal) should only be used when the JSContext is known to accurately
+  // represent the caller.  In practice, that means you should only use them in
+  // two situations at the moment:
+  //
+  // 1) Functions used in WebIDL Func annotations.
+  // 2) Bindings code or other code called directly from the JS engine.
+  //
+  // Use pretty much anywhere else is almost certainly wrong and should be
+  // replaced with [NeedsCallerType] annotations in bindings.
+
+  // Check whether the caller is system if you know you're on the main thread.
+  static bool IsSystemCaller(JSContext* aCx);
+
+  // Check whether the caller is system if you might be on a worker or worklet
+  // thread.
+  static bool ThreadsafeIsSystemCaller(JSContext* aCx);
+
+  // In the traditional Gecko architecture, both C++ code and untrusted JS code
+  // needed to rely on the same XPCOM method/getter/setter to get work done.
+  // This required lots of security checks in the various exposed methods, which
+  // in turn created difficulty in determining whether the caller was script
+  // (whose access needed to be checked) and internal C++ platform code (whose
+  // access did not need to be checked). To address this problem, Gecko had a
+  // convention whereby the absence of script on the stack was interpretted as
+  // "System Caller" and always granted unfettered access.
+  //
+  // Unfortunately, this created a bunch of footguns. For example, when the
+  // implementation of a DOM method wanted to perform a privileged
+  // sub-operation, it needed to "hide" the presence of script on the stack in
+  // order for that sub-operation to be allowed. Additionally, if script could
+  // trigger an API entry point to be invoked in some asynchronous way without
+  // script on the stack, it could potentially perform privilege escalation.
+  //
+  // In the modern world, untrusted script should interact with the platform
+  // exclusively over WebIDL APIs, and platform code has a lot more flexibility
+  // in deciding whether or not to use XPCOM. This gives us the flexibility to
+  // do something better.
+  //
+  // Going forward, APIs should be designed such that any security checks that
+  // ask the question "is my caller allowed to do this?" should live in WebIDL
+  // API entry points, with a separate method provided for internal callers
+  // that just want to get the job done.
+  //
+  // To enforce this and catch bugs, nsContentUtils::SubjectPrincipal will crash
+  // if it is invoked without script on the stack. To land that transition, it
+  // was necessary to go through and whitelist a bunch of callers that were
+  // depending on the old behavior. Those callers should be fixed up, and these
+  // methods should not be used by new code without review from bholley or bz.
+  static bool LegacyIsCallerNativeCode() { return !GetCurrentJSContext(); }
+  static bool LegacyIsCallerChromeOrNativeCode() {
+    return LegacyIsCallerNativeCode() || IsCallerChrome();
+  }
+  static nsIPrincipal* SubjectPrincipalOrSystemIfNativeCaller() {
+    if (!GetCurrentJSContext()) {
+      return GetSystemPrincipal();
+    }
+    return SubjectPrincipal();
+  }
+
+  static bool LookupBindingMember(
+      JSContext* aCx, nsIContent* aContent, JS::Handle<jsid> aId,
+      JS::MutableHandle<JS::PropertyDescriptor> aDesc);
+
+  // Check whether we should avoid leaking distinguishing information to JS/CSS.
+  // This function can be called both in the main thread and worker threads.
+  static bool ShouldResistFingerprinting(
+      RFPTarget aTarget = RFPTarget::Unknown);
+  static bool ShouldResistFingerprinting(nsIGlobalObject* aGlobalObject,
+                                         RFPTarget aTarget);
+  // Similar to the function above, but always allows CallerType::System
+  // callers.
+  static bool ShouldResistFingerprinting(mozilla::dom::CallerType aCallerType,
+                                         nsIGlobalObject* aGlobalObject,
+                                         RFPTarget aTarget);
+  static bool ShouldResistFingerprinting(nsIDocShell* aDocShell,
+                                         RFPTarget aTarget);
+  // These functions are the new, nuanced functions
+  static bool ShouldResistFingerprinting(
+      nsIChannel* aChannel, RFPTarget aTarget = RFPTarget::Unknown);
+  // These functions are labeled as dangerous because they will do the wrong
+  // thing in _most_ cases. They should only be used if you don't have a fully
+  // constructed LoadInfo or Document.
+  // A constant string used as justification is required when calling them,
+  // it should explain why a Document, Channel, LoadInfo, or CookieJarSettings
+  // does not exist in this context.
+  // (see below for more on justification strings.)
+  static bool ShouldResistFingerprinting_dangerous(
+      nsIURI* aURI, const mozilla::OriginAttributes& aOriginAttributes,
+      const char* aJustification, RFPTarget aTarget = RFPTarget::Unknown);
+  static bool ShouldResistFingerprinting_dangerous(
+      nsIPrincipal* aPrincipal, const char* aJustification,
+      RFPTarget aTarget = RFPTarget::Unknown);
+
+  /**
+   * Implement a RFP function that only checks the pref, and does not take
+   * into account any additional context such as PBM mode or Web Extensions.
+   *
+   * It requires an explanation for why the coarse check is being used instead
+   * of the nuanced check. While there is a gradual cut over of
+   * ShouldResistFingerprinting calls to a nuanced API, some features still
+   * require a legacy function. (Additionally, we sometimes use the coarse
+   * check first, to avoid running additional code to support a nuanced check.)
+   */
+  static bool ShouldResistFingerprinting(
+      const char* aJustification, RFPTarget aTarget = RFPTarget::Unknown);
+
+  // A helper function to calculate the rounded window size for fingerprinting
+  // resistance. The rounded size is based on the chrome UI size and available
+  // screen size. If the inputWidth/Height is greater than the available content
+  // size, this will report the available content size. Otherwise, it will
+  // round the size to the nearest upper 200x100.
+  static void CalcRoundedWindowSizeForResistingFingerprinting(
+      int32_t aChromeWidth, int32_t aChromeHeight, int32_t aScreenWidth,
+      int32_t aScreenHeight, int32_t aInputWidth, int32_t aInputHeight,
+      bool aSetOuterWidth, bool aSetOuterHeight, int32_t* aOutputWidth,
+      int32_t* aOutputHeight);
+
+  /**
+   * Returns the parent node of aChild crossing document boundaries, but skips
+   * any cross-process parent frames and continues with the nearest in-process
+   * frame in the hierarchy.
+   *
+   * Uses the parent node in the composed document.
+   */
+  static nsINode* GetNearestInProcessCrossDocParentNode(nsINode* aChild);
+
+  /**
+   * Similar to nsINode::IsInclusiveDescendantOf, except will treat an
+   * HTMLTemplateElement or ShadowRoot as an ancestor of things in the
+   * corresponding DocumentFragment. See the concept of "host-including
+   * inclusive ancestor" in the DOM specification.
+   */
+  static bool ContentIsHostIncludingDescendantOf(
+      const nsINode* aPossibleDescendant, const nsINode* aPossibleAncestor);
+
+  /**
+   * Similar to nsINode::IsInclusiveDescendantOf except it crosses document
+   * boundaries, this function uses ancestor/descendant relations in the
+   * composed document (see shadow DOM spec).
+   */
+  static bool ContentIsCrossDocDescendantOf(nsINode* aPossibleDescendant,
+                                            nsINode* aPossibleAncestor);
+
+  /**
+   * As with ContentIsCrossDocDescendantOf but crosses shadow boundaries but not
+   * cross document boundaries.
+   *
+   * @see nsINode::GetFlattenedTreeParentNode()
+   */
+  static bool ContentIsFlattenedTreeDescendantOf(
+      const nsINode* aPossibleDescendant, const nsINode* aPossibleAncestor);
+
+  /**
+   * Same as `ContentIsFlattenedTreeDescendantOf`, but from the flattened tree
+   * point of view of the style system
+   *
+   * @see nsINode::GetFlattenedTreeParentNodeForStyle()
+   */
+  static bool ContentIsFlattenedTreeDescendantOfForStyle(
+      const nsINode* aPossibleDescendant, const nsINode* aPossibleAncestor);
+
+  /**
+   * Retarget an object A against an object B
+   * @see https://dom.spec.whatwg.org/#retarget
+   */
+  static nsINode* Retarget(nsINode* aTargetA, nsINode* aTargetB);
+
+  /**
+   * @see https://wicg.github.io/element-timing/#get-an-element
+   */
+  static Element* GetAnElementForTiming(Element* aTarget,
+                                        const Document* aDocument,
+                                        nsIGlobalObject* aGlobal);
+
+  /*
+   * https://dom.spec.whatwg.org/#concept-tree-inclusive-ancestor.
+   *
+   * This method fills the |aArray| with all ancestor nodes of |aNode|
+   * including |aNode| at the zero index.
+   *
+   */
+  static nsresult GetInclusiveAncestors(nsINode* aNode,
+                                        nsTArray<nsINode*>& aArray);
+
+  /*
+   * https://dom.spec.whatwg.org/#concept-tree-inclusive-ancestor.
+   *
+   * This method fills |aAncestorNodes| with all ancestor nodes of |aNode|
+   * including |aNode| (QI'd to nsIContent) at the zero index.
+   * For each ancestor, there is a corresponding element in |aAncestorOffsets|
+   * which is the ComputeIndexOf the child in relation to its parent.
+   *
+   * This method just sucks.
+   */
+  static nsresult GetInclusiveAncestorsAndOffsets(
+      nsINode* aNode, uint32_t aOffset, nsTArray<nsIContent*>* aAncestorNodes,
+      nsTArray<mozilla::Maybe<uint32_t>>* aAncestorOffsets);
+
+  /**
+   * Returns the closest common inclusive ancestor
+   * (https://dom.spec.whatwg.org/#concept-tree-inclusive-ancestor) , if any,
+   * for two nodes.
+   *
+   * Returns null if the nodes are disconnected.
+   */
+  static nsINode* GetClosestCommonInclusiveAncestor(nsINode* aNode1,
+                                                    nsINode* aNode2) {
+    if (aNode1 == aNode2) {
+      return aNode1;
+    }
+
+    return GetCommonAncestorHelper(aNode1, aNode2);
+  }
+
+  /**
+   * Returns the common flattened tree ancestor, if any, for two given content
+   * nodes.
+   */
+  static nsIContent* GetCommonFlattenedTreeAncestor(nsIContent* aContent1,
+                                                    nsIContent* aContent2) {
+    if (aContent1 == aContent2) {
+      return aContent1;
+    }
+
+    return GetCommonFlattenedTreeAncestorHelper(aContent1, aContent2);
+  }
+
+  /**
+   * Returns the common flattened tree ancestor from the point of view of the
+   * style system, if any, for two given content nodes.
+   */
+  static Element* GetCommonFlattenedTreeAncestorForStyle(Element* aElement1,
+                                                         Element* aElement2);
+
+  /**
+   * Returns the common ancestor under interactive content, if any.
+   * If neither one has interactive content as ancestor, common ancestor will be
+   * returned. If only one has interactive content as ancestor, null will be
+   * returned. If the nodes are the same, that node is returned.
+   */
+  static nsINode* GetCommonAncestorUnderInteractiveContent(nsINode* aNode1,
+                                                           nsINode* aNode2);
+
+  /**
+   * Returns the common BrowserParent ancestor, if any, for two given
+   * BrowserParent.
+   */
+  static mozilla::dom::BrowserParent* GetCommonBrowserParentAncestor(
+      mozilla::dom::BrowserParent* aBrowserParent1,
+      mozilla::dom::BrowserParent* aBrowserParent2);
+
+  // https://html.spec.whatwg.org/#target-element
+  // https://html.spec.whatwg.org/#find-a-potential-indicated-element
+  static Element* GetTargetElement(Document* aDocument,
+                                   const nsAString& aAnchorName);
+  /**
+   * Returns true if aNode1 is before aNode2 in the same connected
+   * tree.
+   * aNode1Index and aNode2Index are in/out arguments. If non-null, and value is
+   * Some, that value is used instead of calling slow ComputeIndexOf on the
+   * parent node. If value is Nothing, the value will be set to the return value
+   * of ComputeIndexOf.
+   */
+  static bool PositionIsBefore(nsINode* aNode1, nsINode* aNode2,
+                               mozilla::Maybe<uint32_t>* aNode1Index = nullptr,
+                               mozilla::Maybe<uint32_t>* aNode2Index = nullptr);
+
+  struct ComparePointsCache {
+    mozilla::Maybe<uint32_t> ComputeIndexOf(const nsINode* aParent,
+                                            const nsINode* aChild) {
+      if (aParent == mParent && aChild == mChild) {
+        return mIndex;
+      }
+
+      mIndex = aParent->ComputeIndexOf(aChild);
+      mParent = aParent;
+      mChild = aChild;
+      return mIndex;
+    }
+
+   private:
+    const nsINode* mParent = nullptr;
+    const nsINode* mChild = nullptr;
+    mozilla::Maybe<uint32_t> mIndex;
+  };
+
+  /**
+   *  Utility routine to compare two "points", where a point is a node/offset
+   *  pair.
+   *  Pass a cache object as aParent1Cache if you expect to repeatedly
+   *  call this function with the same value as aParent1.
+   *
+   *  @return -1 if point1 < point2,
+   *          1 if point1 > point2,
+   *          0 if point1 == point2.
+   *          `Nothing` if the two nodes aren't in the same connected subtree.
+   */
+  static mozilla::Maybe<int32_t> ComparePoints(
+      const nsINode* aParent1, uint32_t aOffset1, const nsINode* aParent2,
+      uint32_t aOffset2, ComparePointsCache* aParent1Cache = nullptr);
+  template <typename FPT, typename FRT, typename SPT, typename SRT>
+  static mozilla::Maybe<int32_t> ComparePoints(
+      const mozilla::RangeBoundaryBase<FPT, FRT>& aFirstBoundary,
+      const mozilla::RangeBoundaryBase<SPT, SRT>& aSecondBoundary);
+
+  /**
+   *  Utility routine to compare two "points", where a point is a
+   *  node/offset pair
+   *  Returns -1 if point1 < point2, 1, if point1 > point2,
+   *  0 if error or if point1 == point2.
+   *  NOTE! If the two nodes aren't in the same connected subtree,
+   *  the result is 1, and the optional aDisconnected parameter
+   *  is set to true.
+   *
+   *  Pass a cache object as aParent1Cache if you expect to repeatedly
+   *  call this function with the same value as aParent1.
+   */
+  static int32_t ComparePoints_Deprecated(
+      const nsINode* aParent1, uint32_t aOffset1, const nsINode* aParent2,
+      uint32_t aOffset2, bool* aDisconnected = nullptr,
+      ComparePointsCache* aParent1Cache = nullptr);
+  template <typename FPT, typename FRT, typename SPT, typename SRT>
+  static int32_t ComparePoints_Deprecated(
+      const mozilla::RangeBoundaryBase<FPT, FRT>& aFirstBoundary,
+      const mozilla::RangeBoundaryBase<SPT, SRT>& aSecondBoundary,
+      bool* aDisconnected = nullptr);
+
+  /**
+   * DO NOT USE this method for comparing the points in new code.  this method
+   * emulates same result as `ComparePoints` before bug 1741148.
+   * When the old `ComparePoints` was called with offset value over `INT32_MAX`
+   * or `-1` which is used as "not found" by some API, they were treated as-is
+   * without checking whether the negative value or valid value.  Thus, this
+   * handles the negative offset cases in the special paths to keep the
+   * traditional behavior. If you want to use this in new code, it means that
+   * you **should** check the offset values and call `ComparePoints` instead.
+   */
+  static mozilla::Maybe<int32_t> ComparePoints_AllowNegativeOffsets(
+      const nsINode* aParent1, int64_t aOffset1, const nsINode* aParent2,
+      int64_t aOffset2) {
+    if (MOZ_UNLIKELY(aOffset1 < 0 || aOffset2 < 0)) {
+      // If in same container, just the offset is compared.
+      if (aParent1 == aParent2) {
+        const int32_t compOffsets =
+            aOffset1 == aOffset2 ? 0 : (aOffset1 < aOffset2 ? -1 : 1);
+        return mozilla::Some(compOffsets);
+      }
+      // Otherwise, aOffset1 is referred only when aParent2 is a descendant of
+      // aParent1.
+      if (aOffset1 < 0 && aParent2->IsInclusiveDescendantOf(aParent1)) {
+        return mozilla::Some(-1);
+      }
+      // And also aOffset2 is referred only when aParent1 is a descendant of
+      // aParent2.
+      if (aOffset2 < 0 && aParent1->IsInclusiveDescendantOf(aParent2)) {
+        return mozilla::Some(1);
+      }
+      // Otherwise, aOffset1 nor aOffset2 is referred so that any value is fine
+      // if negative.
+      return ComparePoints(
+          aParent1, aOffset1 < 0 ? UINT32_MAX : static_cast<uint32_t>(aOffset1),
+          aParent2,
+          aOffset2 < 0 ? UINT32_MAX : static_cast<uint32_t>(aOffset2));
+    }
+    return ComparePoints(aParent1, aOffset1, aParent2, aOffset2);
+  }
+
+  /**
+   * Brute-force search of the element subtree rooted at aContent for
+   * an element with the given id.  aId must be nonempty, otherwise
+   * this method may return nodes even if they have no id!
+   */
+  static Element* MatchElementId(nsIContent* aContent, const nsAString& aId);
+
+  /**
+   * Similar to above, but to be used if one already has an atom for the ID
+   */
+  static Element* MatchElementId(nsIContent* aContent, const nsAtom* aId);
+
+  /**
+   * Reverses the document position flags passed in.
+   *
+   * @param   aDocumentPosition   The document position flags to be reversed.
+   *
+   * @return  The reversed document position flags.
+   *
+   * @see Node
+   */
+  static uint16_t ReverseDocumentPosition(uint16_t aDocumentPosition);
+
+  static const nsDependentSubstring TrimCharsInSet(const char* aSet,
+                                                   const nsAString& aValue);
+
+  template <bool IsWhitespace(char16_t)>
+  static const nsDependentSubstring TrimWhitespace(const nsAString& aStr,
+                                                   bool aTrimTrailing = true);
+
+  /**
+   * Returns true if aChar is of class Ps, Pi, Po, Pf, or Pe.
+   */
+  static bool IsFirstLetterPunctuation(uint32_t aChar);
+
+  /**
+   * Returns true if aChar is of class Lu, Ll, Lt, Lm, Lo, Nd, Nl or No
+   */
+  static bool IsAlphanumeric(uint32_t aChar);
+  /**
+   * Returns true if aChar is of class L*, N* or S* (for first-letter).
+   */
+  static bool IsAlphanumericOrSymbol(uint32_t aChar);
+
+  /*
+   * Is the character an HTML whitespace character?
+   *
+   * We define whitespace using the list in HTML5 and css3-selectors:
+   * U+0009, U+000A, U+000C, U+000D, U+0020
+   *
+   * HTML 4.01 also lists U+200B (zero-width space).
+   */
+  static bool IsHTMLWhitespace(char16_t aChar);
+
+  /*
+   * Returns whether the character is an HTML whitespace (see IsHTMLWhitespace)
+   * or a nbsp character (U+00A0).
+   */
+  static bool IsHTMLWhitespaceOrNBSP(char16_t aChar);
+
+  /**
+   * https://developer.mozilla.org/en-US/docs/Web/HTML/Block-level_elements
+   */
+  static bool IsHTMLBlockLevelElement(nsIContent* aContent);
+
+  enum ParseHTMLIntegerResultFlags {
+    eParseHTMLInteger_NoFlags = 0,
+    // eParseHTMLInteger_NonStandard is set if the string representation of the
+    // integer was not the canonical one, but matches at least one of the
+    // following:
+    //   * had leading whitespaces
+    //   * had '+' sign
+    //   * had leading '0'
+    //   * was '-0'
+    eParseHTMLInteger_NonStandard = 1 << 0,
+    eParseHTMLInteger_DidNotConsumeAllInput = 1 << 1,
+    // Set if one or more error flags were set.
+    eParseHTMLInteger_Error = 1 << 2,
+    eParseHTMLInteger_ErrorNoValue = 1 << 3,
+    eParseHTMLInteger_ErrorOverflow = 1 << 4,
+    // Use this flag to detect the difference between overflow and underflow
+    eParseHTMLInteger_Negative = 1 << 5,
+  };
+  static int32_t ParseHTMLInteger(const nsAString& aValue,
+                                  ParseHTMLIntegerResultFlags* aResult) {
+    return ParseHTMLInteger(aValue.BeginReading(), aValue.EndReading(),
+                            aResult);
+  }
+  static int32_t ParseHTMLInteger(const char16_t* aStart, const char16_t* aEnd,
+                                  ParseHTMLIntegerResultFlags* aResult);
+  static int32_t ParseHTMLInteger(const nsACString& aValue,
+                                  ParseHTMLIntegerResultFlags* aResult) {
+    return ParseHTMLInteger(aValue.BeginReading(), aValue.EndReading(),
+                            aResult);
+  }
+  static int32_t ParseHTMLInteger(const char* aStart, const char* aEnd,
+                                  ParseHTMLIntegerResultFlags* aResult);
+
+ private:
+  template <class CharT>
+  static int32_t ParseHTMLIntegerImpl(const CharT* aStart, const CharT* aEnd,
+                                      ParseHTMLIntegerResultFlags* aResult);
+
+ public:
+  /**
+   * Parse a margin string of format 'top, right, bottom, left' into
+   * an nsIntMargin.
+   *
+   * @param aString the string to parse
+   * @param aResult the resulting integer
+   * @return whether the value could be parsed
+   */
+  static bool ParseIntMarginValue(const nsAString& aString,
+                                  nsIntMargin& aResult);
+
+  /**
+   * Parse the value of the <font size=""> attribute according to the HTML5
+   * spec as of April 16, 2012.
+   *
+   * @param aValue the value to parse
+   * @return 1 to 7, or 0 if the value couldn't be parsed
+   */
+  static int32_t ParseLegacyFontSize(const nsAString& aValue);
+
+  static void Shutdown();
+
+  /**
+   * Checks whether two nodes come from the same origin.
+   */
+  static nsresult CheckSameOrigin(const nsINode* aTrustedNode,
+                                  const nsINode* unTrustedNode);
+
+  // Check if the (JS) caller can access aNode.
+  static bool CanCallerAccess(const nsINode* aNode);
+
+  // Check if the (JS) caller can access aWindow.
+  // aWindow can be either outer or inner window.
+  static bool CanCallerAccess(nsPIDOMWindowInner* aWindow);
+
+  // Check if the principal is chrome or an addon with the permission.
+  static bool PrincipalHasPermission(nsIPrincipal& aPrincipal,
+                                     const nsAtom* aPerm);
+
+  // Check if the JS caller is chrome or an addon with the permission.
+  static bool CallerHasPermission(JSContext* aCx, const nsAtom* aPerm);
+
+  /**
+   * Returns the triggering principal which should be used for the given URL
+   * attribute value with the given subject principal.
+   *
+   * If the attribute value is not an absolute URL, the subject principal will
+   * be ignored, and the node principal of aContent will be used instead.
+   * If aContent is non-null, this function will always return a principal.
+   * Otherewise, it may return null if aSubjectPrincipal is null or is rejected
+   * based on the attribute value.
+   *
+   * @param aContent The content on which the attribute is being set.
+   * @param aAttrValue The URL value of the attribute. For parsed attribute
+   *        values, such as `srcset`, this function should be called separately
+   *        for each URL value it contains.
+   * @param aSubjectPrincipal The subject principal of the scripted caller
+   *        responsible for setting the attribute, or null if no scripted caller
+   *        can be determined.
+   */
+  static nsIPrincipal* GetAttrTriggeringPrincipal(
+      nsIContent* aContent, const nsAString& aAttrValue,
+      nsIPrincipal* aSubjectPrincipal);
+
+  /**
+   * Returns true if the given string is guaranteed to be treated as an absolute
+   * URL, rather than a relative URL. In practice, this means any complete URL
+   * as supported by nsStandardURL, or any string beginning with a valid scheme
+   * which is known to the IO service, and has the URI_NORELATIVE flag.
+   *
+   * If the URL may be treated as absolute in some cases, but relative in others
+   * (for instance, "http:foo", which can be either an absolute or relative URL,
+   * depending on the context), this function returns false.
+   */
+  static bool IsAbsoluteURL(const nsACString& aURL);
+
+  // Check if a node is in the document prolog, i.e. before the document
+  // element.
+  static bool InProlog(nsINode* aNode);
+
+  static nsIBidiKeyboard* GetBidiKeyboard();
+
+  /**
+   * Get the cache security manager service. Can return null if the layout
+   * module has been shut down.
+   */
+  static nsIScriptSecurityManager* GetSecurityManager() {
+    return sSecurityManager;
+  }
+
+  // Returns the subject principal from the JSContext. May only be called
+  // from the main thread and assumes an existing compartment.
+  static nsIPrincipal* SubjectPrincipal(JSContext* aCx);
+
+  // Returns the subject principal. Guaranteed to return non-null. May only
+  // be called when nsContentUtils is initialized.
+  static nsIPrincipal* SubjectPrincipal();
+
+  // Returns the prinipal of the given JS object. This may only be called on
+  // the main thread for objects from the main thread's JSRuntime. The object
+  // must not be a cross-compartment wrapper, because CCWs are not associated
+  // with a single realm.
+  static nsIPrincipal* ObjectPrincipal(JSObject* aObj);
+
+  static void GenerateStateKey(nsIContent* aContent, Document* aDocument,
+                               nsACString& aKey);
+
+  /**
+   * Create a new nsIURI from aSpec, using aBaseURI as the base.  The
+   * origin charset of the new nsIURI will be the document charset of
+   * aDocument.
+   */
+  static nsresult NewURIWithDocumentCharset(nsIURI** aResult,
+                                            const nsAString& aSpec,
+                                            Document* aDocument,
+                                            nsIURI* aBaseURI);
+
+  /**
+   * Returns true if |aName| is a name with dashes.
+   */
+  static bool IsNameWithDash(nsAtom* aName);
+
+  /**
+   * Returns true if |aName| is a valid name to be registered via
+   * customElements.define.
+   */
+  static bool IsCustomElementName(nsAtom* aName, uint32_t aNameSpaceID);
+
+  static nsresult CheckQName(const nsAString& aQualifiedName,
+                             bool aNamespaceAware = true,
+                             const char16_t** aColon = nullptr);
+
+  static nsresult SplitQName(const nsIContent* aNamespaceResolver,
+                             const nsString& aQName, int32_t* aNamespace,
+                             nsAtom** aLocalName);
+
+  static nsresult GetNodeInfoFromQName(const nsAString& aNamespaceURI,
+                                       const nsAString& aQualifiedName,
+                                       nsNodeInfoManager* aNodeInfoManager,
+                                       uint16_t aNodeType,
+                                       mozilla::dom::NodeInfo** aNodeInfo);
+
+  static void SplitExpatName(const char16_t* aExpatName, nsAtom** aPrefix,
+                             nsAtom** aTagName, int32_t* aNameSpaceID);
+
+  // Get a permission-manager setting for the given principal and type.
+  // If the pref doesn't exist or if it isn't ALLOW_ACTION, false is
+  // returned, otherwise true is returned. Always returns true for the
+  // system principal, and false for a null principal.
+  static bool IsSitePermAllow(nsIPrincipal* aPrincipal,
+                              const nsACString& aType);
+
+  // Get a permission-manager setting for the given principal and type.
+  // If the pref doesn't exist or if it isn't DENY_ACTION, false is
+  // returned, otherwise true is returned. Always returns false for the
+  // system principal, and true for a null principal.
+  static bool IsSitePermDeny(nsIPrincipal* aPrincipal, const nsACString& aType);
+
+  // Get a permission-manager setting for the given principal and type.
+  // If the pref doesn't exist or if it isn't ALLOW_ACTION, false is
+  // returned, otherwise true is returned. Always returns true for the
+  // system principal, and false for a null principal.
+  // This version checks the permission for an exact host match on
+  // the principal
+  static bool IsExactSitePermAllow(nsIPrincipal* aPrincipal,
+                                   const nsACString& aType);
+
+  // Get a permission-manager setting for the given principal and type.
+  // If the pref doesn't exist or if it isn't DENY_ACTION, false is
+  // returned, otherwise true is returned. Always returns false for the
+  // system principal, and true for a null principal.
+  // This version checks the permission for an exact host match on
+  // the principal
+  static bool IsExactSitePermDeny(nsIPrincipal* aPrincipal,
+                                  const nsACString& aType);
+
+  // Returns true if the pref exists and is not UNKNOWN_ACTION.
+  static bool HasSitePerm(nsIPrincipal* aPrincipal, const nsACString& aType);
+
+  // Returns true if aDoc1 and aDoc2 have equal NodePrincipal()s.
+  static bool HaveEqualPrincipals(Document* aDoc1, Document* aDoc2);
+
+  /**
+   * Regster aObserver as a shutdown observer. A strong reference is held
+   * to aObserver until UnregisterShutdownObserver is called.
+   */
+  static void RegisterShutdownObserver(nsIObserver* aObserver);
+  static void UnregisterShutdownObserver(nsIObserver* aObserver);
+
+  /**
+   * @return true if aContent has an attribute aName in namespace aNameSpaceID,
+   * and the attribute value is non-empty.
+   */
+  static bool HasNonEmptyAttr(const nsIContent* aContent, int32_t aNameSpaceID,
+                              nsAtom* aName);
+
+  /**
+   * Method that gets the primary presContext for the node.
+   *
+   * @param aContent The content node.
+   * @return the presContext, or nullptr if the content is not in a document
+   *         (if GetComposedDoc returns nullptr)
+   */
+  static nsPresContext* GetContextForContent(const nsIContent* aContent);
+
+  /**
+   * Method that gets the pres shell for the node.
+   *
+   * @param aContent The content node.
+   * @return the pres shell, or nullptr if the content is not in a document
+   *         (if GetComposedDoc returns nullptr)
+   */
+  static mozilla::PresShell* GetPresShellForContent(const nsIContent* aContent);
+
+  /**
+   * Method to do security and content policy checks on the image URI
+   *
+   * @param aURI uri of the image to be loaded
+   * @param aNode, the context the image is loaded in (eg an element)
+   * @param aLoadingDocument the document we belong to
+   * @param aLoadingPrincipal the principal doing the load
+   * @param [aContentPolicyType=nsIContentPolicy::TYPE_INTERNAL_IMAGE]
+   * (Optional) The CP content type to use
+   * @param aImageBlockingStatus the nsIContentPolicy blocking status for this
+   *        image.  This will be set even if a security check fails for the
+   *        image, to some reasonable REJECT_* value.  This out param will only
+   *        be set if it's non-null.
+   * @return true if the load can proceed, or false if it is blocked.
+   *         Note that aImageBlockingStatus, if set will always be an ACCEPT
+   *         status if true is returned and always be a REJECT_* status if
+   *         false is returned.
+   */
+  static bool CanLoadImage(nsIURI* aURI, nsINode* aNode,
+                           Document* aLoadingDocument,
+                           nsIPrincipal* aLoadingPrincipal);
+
+  /**
+   * Returns true if objects in aDocument shouldn't initiate image loads.
+   */
+  static bool DocumentInactiveForImageLoads(Document* aDocument);
+
+  /**
+   * Convert a CORSMode into the corresponding imgILoader flags for
+   * passing to LoadImage.
+   * @param aMode CORS mode to convert
+   * @return a bitfield suitable to bitwise OR with other nsIRequest flags
+   */
+  static int32_t CORSModeToLoadImageFlags(mozilla::CORSMode aMode);
+
+  /**
+   * Method to start an image load.  This does not do any security checks.
+   * This method will attempt to make aURI immutable; a caller that wants to
+   * keep a mutable version around should pass in a clone.
+   *
+   * @param aURI uri of the image to be loaded
+   * @param aContext element of document where the result of this request
+   *                 will be used.
+   * @param aLoadingDocument the document we belong to
+   * @param aLoadingPrincipal the principal doing the load
+   * @param aReferrerInfo the referrerInfo use on channel creation
+   * @param aObserver the observer for the image load
+   * @param aLoadFlags the load flags to use.  See nsIRequest
+   * @param [aContentPolicyType=nsIContentPolicy::TYPE_INTERNAL_IMAGE]
+   * (Optional) The CP content type to use
+   * @param aUseUrgentStartForChannel,(Optional) a flag to mark on channel if it
+   *        is triggered by user input events.
+   * @return the imgIRequest for the image load
+   */
+  static nsresult LoadImage(
+      nsIURI* aURI, nsINode* aContext, Document* aLoadingDocument,
+      nsIPrincipal* aLoadingPrincipal, uint64_t aRequestContextID,
+      nsIReferrerInfo* aReferrerInfo, imgINotificationObserver* aObserver,
+      int32_t aLoadFlags, const nsAString& initiatorType,
+      imgRequestProxy** aRequest,
+      nsContentPolicyType aContentPolicyType =
+          nsIContentPolicy::TYPE_INTERNAL_IMAGE,
+      bool aUseUrgentStartForChannel = false, bool aLinkPreload = false,
+      uint64_t aEarlyHintPreloaderId = 0);
+
+  /**
+   * Obtain an image loader that respects the given document/channel's privacy
+   * status. Null document/channel arguments return the public image loader.
+   */
+  static imgLoader* GetImgLoaderForDocument(Document* aDoc);
+  static imgLoader* GetImgLoaderForChannel(nsIChannel* aChannel,
+                                           Document* aContext);
+
+  /**
+   * Method to get an imgIContainer from an image loading content
+   *
+   * @param aContent The image loading content.  Must not be null.
+   * @param aRequest The image request [out]
+   * @return the imgIContainer corresponding to the first frame of the image
+   */
+  static already_AddRefed<imgIContainer> GetImageFromContent(
+      nsIImageLoadingContent* aContent, imgIRequest** aRequest = nullptr);
+
+  /**
+   * Method that decides whether a content node is draggable
+   *
+   * @param aContent The content node to test.
+   * @return whether it's draggable
+   */
+  static bool ContentIsDraggable(nsIContent* aContent);
+
+  /**
+   * Method that decides whether a content node is a draggable image
+   *
+   * @param aContent The content node to test.
+   * @return whether it's a draggable image
+   */
+  static bool IsDraggableImage(nsIContent* aContent);
+
+  /**
+   * Method that decides whether a content node is a draggable link
+   *
+   * @param aContent The content node to test.
+   * @return whether it's a draggable link
+   */
+  static bool IsDraggableLink(const nsIContent* aContent);
+
+  /**
+   * Convenience method to create a new nodeinfo that differs only by prefix and
+   * name from aNodeInfo. The new nodeinfo's name is set to aName, and prefix is
+   * set to null.
+   */
+  static nsresult QNameChanged(mozilla::dom::NodeInfo* aNodeInfo, nsAtom* aName,
+                               mozilla::dom::NodeInfo** aResult);
+
+  /**
+   * Returns the appropriate event argument names for the specified
+   * namespace and event name.  Added because we need to switch between
+   * SVG's "evt" and the rest of the world's "event", and because onerror
+   * on window takes 5 args.
+   */
+  static void GetEventArgNames(int32_t aNameSpaceID, nsAtom* aEventName,
+                               bool aIsForWindow, uint32_t* aArgCount,
+                               const char*** aArgNames);
+
+  /**
+   * Returns true if this document is in a Private Browsing window.
+   */
+  static bool IsInPrivateBrowsing(Document* aDoc);
+
+  /**
+   * Returns true if this loadGroup uses Private Browsing.
+   */
+  static bool IsInPrivateBrowsing(nsILoadGroup* aLoadGroup);
+
+  /**
+   * Returns whether a node is in the same tree as another one, accounting for
+   * anonymous roots.
+   *
+   * This method is particularly useful for callers who are trying to ensure
+   * that they are working with a non-anonymous descendant of a given node.  If
+   * aContent is a descendant of aNode, a return value of false from this
+   * method means that it's an anonymous descendant from aNode's point of view.
+   *
+   * Both arguments to this method must be non-null.
+   */
+  static bool IsInSameAnonymousTree(const nsINode* aNode,
+                                    const nsINode* aOtherNode);
+
+  /*
+   * Traverse the parent chain from aElement up to aStop, and return true if
+   * there's an interactive html content; false otherwise.
+   *
+   * Note: This crosses shadow boundaries but not document boundaries.
+   */
+  static bool IsInInteractiveHTMLContent(const Element* aElement,
+                                         const Element* aStop);
+
+  /**
+   * Return the nsIXPConnect service.
+   */
+  static nsIXPConnect* XPConnect() { return sXPConnect; }
+
+  /**
+   * Report simple error message to the browser console
+   *   @param aErrorText the error message
+   *   @param aCategory Name of the module reporting error
+   *   @param aFromPrivateWindow Whether from private window or not
+   *   @param aFromChromeContext Whether from chrome context or not
+   *   @param [aErrorFlags] See nsIScriptError.
+   */
+  static void LogSimpleConsoleError(
+      const nsAString& aErrorText, const nsACString& aCategory,
+      bool aFromPrivateWindow, bool aFromChromeContext,
+      uint32_t aErrorFlags = nsIScriptError::errorFlag);
+
+  /**
+   * Report a non-localized error message to the error console.
+   *   @param aErrorText the error message
+   *   @param aErrorFlags See nsIScriptError.
+   *   @param aCategory Name of module reporting error.
+   *   @param aDocument Reference to the document which triggered the message.
+   *   @param [aURI=nullptr] (Optional) URI of resource containing error.
+   *   @param [aSourceLine=u""_ns] (Optional) The text of the line that
+              contains the error (may be empty).
+   *   @param [aLineNumber=0] (Optional) Line number within resource
+              containing error.
+   *   @param [aColumnNumber=0] (Optional) Column number within resource
+              containing error.
+              If aURI is null, then aDocument->GetDocumentURI() is used.
+   *   @param [aLocationMode] (Optional) Specifies the behavior if
+              error location information is omitted.
+   */
+  enum MissingErrorLocationMode {
+    // Don't show location information in the error console.
+    eOMIT_LOCATION,
+    // Get location information from the currently executing script.
+    eUSE_CALLING_LOCATION
+  };
+  static nsresult ReportToConsoleNonLocalized(
+      const nsAString& aErrorText, uint32_t aErrorFlags,
+      const nsACString& aCategory, const Document* aDocument,
+      nsIURI* aURI = nullptr, const nsString& aSourceLine = u""_ns,
+      uint32_t aLineNumber = 0, uint32_t aColumnNumber = 0,
+      MissingErrorLocationMode aLocationMode = eUSE_CALLING_LOCATION);
+
+  /**
+   * Report a non-localized error message to the error console base on the
+   * innerWindowID.
+   *   @param aErrorText the error message
+   *   @param aErrorFlags See nsIScriptError.
+   *   @param aCategory Name of module reporting error.
+   *   @param [aInnerWindowID] Inner window ID for document which triggered the
+   *          message.
+   *   @param [aURI=nullptr] (Optional) URI of resource containing error.
+   *   @param [aSourceLine=u""_ns] (Optional) The text of the line that
+              contains the error (may be empty).
+   *   @param [aLineNumber=0] (Optional) Line number within resource
+              containing error.
+   *   @param [aColumnNumber=0] (Optional) Column number within resource
+              containing error.
+              If aURI is null, then aDocument->GetDocumentURI() is used.
+   *   @param [aLocationMode] (Optional) Specifies the behavior if
+              error location information is omitted.
+   */
+  static nsresult ReportToConsoleByWindowID(
+      const nsAString& aErrorText, uint32_t aErrorFlags,
+      const nsACString& aCategory, uint64_t aInnerWindowID,
+      nsIURI* aURI = nullptr, const nsString& aSourceLine = u""_ns,
+      uint32_t aLineNumber = 0, uint32_t aColumnNumber = 0,
+      MissingErrorLocationMode aLocationMode = eUSE_CALLING_LOCATION);
+
+  /**
+   * Report a localized error message to the error console.
+   *   @param aErrorFlags See nsIScriptError.
+   *   @param aCategory Name of module reporting error.
+   *   @param aDocument Reference to the document which triggered the message.
+   *   @param aFile Properties file containing localized message.
+   *   @param aMessageName Name of localized message.
+   *   @param [aParams=empty-array] (Optional) Parameters to be substituted into
+              localized message.
+   *   @param [aURI=nullptr] (Optional) URI of resource containing error.
+   *   @param [aSourceLine=u""_ns] (Optional) The text of the line that
+              contains the error (may be empty).
+   *   @param [aLineNumber=0] (Optional) Line number within resource
+              containing error.
+   *   @param [aColumnNumber=0] (Optional) Column number within resource
+              containing error.
+              If aURI is null, then aDocument->GetDocumentURI() is used.
+   */
+  enum PropertiesFile {
+    eCSS_PROPERTIES,
+    eXUL_PROPERTIES,
+    eLAYOUT_PROPERTIES,
+    eFORMS_PROPERTIES,
+    ePRINTING_PROPERTIES,
+    eDOM_PROPERTIES,
+    eHTMLPARSER_PROPERTIES,
+    eSVG_PROPERTIES,
+    eBRAND_PROPERTIES,
+    eCOMMON_DIALOG_PROPERTIES,
+    eMATHML_PROPERTIES,
+    eSECURITY_PROPERTIES,
+    eNECKO_PROPERTIES,
+    eFORMS_PROPERTIES_en_US,
+    eDOM_PROPERTIES_en_US,
+    PropertiesFile_COUNT
+  };
+  static nsresult ReportToConsole(
+      uint32_t aErrorFlags, const nsACString& aCategory,
+      const Document* aDocument, PropertiesFile aFile, const char* aMessageName,
+      const nsTArray<nsString>& aParams = nsTArray<nsString>(),
+      nsIURI* aURI = nullptr, const nsString& aSourceLine = u""_ns,
+      uint32_t aLineNumber = 0, uint32_t aColumnNumber = 0);
+
+  static void ReportEmptyGetElementByIdArg(const Document* aDoc);
+
+  static void LogMessageToConsole(const char* aMsg);
+
+  static bool SpoofLocaleEnglish();
+
+  /**
+   * Get the localized string named |aKey| in properties file |aFile|.
+   */
+  static nsresult GetLocalizedString(PropertiesFile aFile, const char* aKey,
+                                     nsAString& aResult);
+
+  /**
+   * Same as GetLocalizedString, except that it might use en-US locale depending
+   * on SpoofLocaleEnglish() and whether the document is a built-in browser
+   * page.
+   */
+  static nsresult GetMaybeLocalizedString(PropertiesFile aFile,
+                                          const char* aKey, Document* aDocument,
+                                          nsAString& aResult);
+
+  /**
+   * A helper function that parses a sandbox attribute (of an <iframe> or a CSP
+   * directive) and converts it to the set of flags used internally.
+   *
+   * @param aSandboxAttr  the sandbox attribute
+   * @return              the set of flags (SANDBOXED_NONE if aSandboxAttr is
+   *                      null)
+   */
+  static uint32_t ParseSandboxAttributeToFlags(const nsAttrValue* aSandboxAttr);
+
+  /**
+   * A helper function that checks if a string matches a valid sandbox flag.
+   *
+   * @param aFlag   the potential sandbox flag.
+   * @return        true if the flag is a sandbox flag.
+   */
+  static bool IsValidSandboxFlag(const nsAString& aFlag);
+
+  /**
+   * A helper function that returns a string attribute corresponding to the
+   * sandbox flags.
+   *
+   * @param aFlags    the sandbox flags
+   * @param aString   the attribute corresponding to the flags (null if aFlags
+   *                  is zero)
+   */
+  static void SandboxFlagsToString(uint32_t aFlags, nsAString& aString);
+
+  static bool PrefetchPreloadEnabled(nsIDocShell* aDocShell);
+
+  static void ExtractErrorValues(JSContext* aCx, JS::Handle<JS::Value> aValue,
+                                 nsAString& aSourceSpecOut, uint32_t* aLineOut,
+                                 uint32_t* aColumnOut, nsString& aMessageOut);
+
+  // Variant on `ExtractErrorValues` with a `nsACString`. This
+  // method is provided for backwards compatibility. Prefer the
+  // faster method above for your code.
+  static void ExtractErrorValues(JSContext* aCx, JS::Handle<JS::Value> aValue,
+                                 nsACString& aSourceSpecOut, uint32_t* aLineOut,
+                                 uint32_t* aColumnOut, nsString& aMessageOut);
+
+  static nsresult CalculateBufferSizeForImage(
+      const uint32_t& aStride, const mozilla::gfx::IntSize& aImageSize,
+      const mozilla::gfx::SurfaceFormat& aFormat, size_t* aMaxBufferSize,
+      size_t* aUsedBufferSize);
+
+  // Returns true if the URI's host is contained in a list which is a comma
+  // separated domain list.  Each item may start with "*.".  If starts with
+  // "*.", it matches any sub-domains.
+  // The aList argument must be a lower-case string.
+  static bool IsURIInList(nsIURI* aURI, const nsCString& aList);
+
+  // Returns true if the URI's host is contained in a pref list which is a comma
+  // separated domain list.  Each item may start with "*.".  If starts with
+  // "*.", it matches any sub-domains.
+  static bool IsURIInPrefList(nsIURI* aURI, const char* aPrefName);
+
+  /*&
+   * A convenience version of FormatLocalizedString that can be used if all the
+   * params are in same-typed strings.  The variadic template args need to come
+   * at the end, so we put aResult at the beginning to make sure it's clear
+   * which is the output and which are the inputs.
+   */
+  template <typename... T>
+  static nsresult FormatLocalizedString(nsAString& aResult,
+                                        PropertiesFile aFile, const char* aKey,
+                                        const T&... aParams) {
+    static_assert(sizeof...(aParams) != 0, "Use GetLocalizedString()");
+    AutoTArray<nsString, sizeof...(aParams)> params = {
+        aParams...,
+    };
+    return FormatLocalizedString(aFile, aKey, params, aResult);
+  }
+
+  /**
+   * Same as FormatLocalizedString template version, except that it might use
+   * en-US locale depending on SpoofLocaleEnglish() and whether the document is
+   * a built-in browser page.
+   */
+  template <typename... T>
+  static nsresult FormatMaybeLocalizedString(nsAString& aResult,
+                                             PropertiesFile aFile,
+                                             const char* aKey,
+                                             Document* aDocument,
+                                             const T&... aParams) {
+    static_assert(sizeof...(aParams) != 0, "Use GetMaybeLocalizedString()");
+    AutoTArray<nsString, sizeof...(aParams)> params = {
+        aParams...,
+    };
+    return FormatMaybeLocalizedString(aFile, aKey, aDocument, params, aResult);
+  }
+
+  /**
+   * Fill (with the parameters given) the localized string named |aKey| in
+   * properties file |aFile| consuming an nsTArray of nsString parameters rather
+   * than a char16_t** for the sake of avoiding use-after-free errors involving
+   * temporaries.
+   */
+  static nsresult FormatLocalizedString(PropertiesFile aFile, const char* aKey,
+                                        const nsTArray<nsString>& aParamArray,
+                                        nsAString& aResult);
+
+  /**
+   * Same as FormatLocalizedString, except that it might use en-US locale
+   * depending on SpoofLocaleEnglish() and whether the document is a built-in
+   * browser page.
+   */
+  static nsresult FormatMaybeLocalizedString(
+      PropertiesFile aFile, const char* aKey, Document* aDocument,
+      const nsTArray<nsString>& aParamArray, nsAString& aResult);
+
+  /**
+   * Returns true if aDocument is a chrome document
+   */
+  static bool IsChromeDoc(const Document* aDocument);
+
+  /**
+   * Returns true if aDocument is in a docshell whose parent is the same type
+   */
+  static bool IsChildOfSameType(Document* aDoc);
+
+  /**
+   * Returns true if the content-type will be rendered as plain-text.
+   */
+  static bool IsPlainTextType(const nsACString& aContentType);
+
+  /**
+   * Returns true iff the type is rendered as plain text and doesn't support
+   * non-UTF-8 encodings.
+   */
+  static bool IsUtf8OnlyPlainTextType(const nsACString& aContentType);
+
+  /**
+   * Returns true if aDocument belongs to a chrome docshell for
+   * display purposes.  Returns false for null documents or documents
+   * which do not belong to a docshell.
+   */
+  static bool IsInChromeDocshell(const Document* aDocument);
+
+  /**
+   * Return the content policy service
+   */
+  static nsIContentPolicy* GetContentPolicy();
+
+  /**
+   * Map internal content policy types to external ones.
+   */
+  static inline ExtContentPolicyType InternalContentPolicyTypeToExternal(
+      nsContentPolicyType aType);
+
+  /**
+   * check whether the Link header field applies to the context resource
+   * see <http://tools.ietf.org/html/rfc5988#section-5.2>
+   */
+  static bool LinkContextIsURI(const nsAString& aAnchor, nsIURI* aDocURI);
+
+  /**
+   * Returns true if the content policy type is any of:
+   *   * TYPE_INTERNAL_SCRIPT_PRELOAD
+   *   * TYPE_INTERNAL_IMAGE_PRELOAD
+   *   * TYPE_INTERNAL_STYLESHEET_PRELOAD
+   */
+  static bool IsPreloadType(nsContentPolicyType aType);
+
+  /**
+   * Quick helper to determine whether there are any mutation listeners
+   * of a given type that apply to this content or any of its ancestors.
+   * The method has the side effect to call document's MayDispatchMutationEvent
+   * using aTargetForSubtreeModified as the parameter.
+   *
+   * @param aNode  The node to search for listeners
+   * @param aType  The type of listener (NS_EVENT_BITS_MUTATION_*)
+   * @param aTargetForSubtreeModified The node which is the target of the
+   *                                  possible DOMSubtreeModified event.
+   *
+   * @return true if there are mutation listeners of the specified type
+   */
+  static bool HasMutationListeners(nsINode* aNode, uint32_t aType,
+                                   nsINode* aTargetForSubtreeModified);
+
+  /**
+   * Quick helper to determine whether there are any mutation listeners
+   * of a given type that apply to any content in this document. It is valid
+   * to pass null for aDocument here, in which case this function always
+   * returns true.
+   *
+   * @param aDocument The document to search for listeners
+   * @param aType     The type of listener (NS_EVENT_BITS_MUTATION_*)
+   *
+   * @return true if there are mutation listeners of the specified type
+   */
+  static bool HasMutationListeners(Document* aDocument, uint32_t aType);
+  /**
+   * Synchronously fire DOMNodeRemoved on aChild. Only fires the event if
+   * there really are listeners by checking using the HasMutationListeners
+   * function above. The function makes sure to hold the relevant objects alive
+   * for the duration of the event firing. However there are no guarantees
+   * that any of the objects are alive by the time the function returns.
+   * If you depend on that you need to hold references yourself.
+   *
+   * @param aChild    The node to fire DOMNodeRemoved at.
+   * @param aParent   The parent of aChild.
+   */
+  MOZ_CAN_RUN_SCRIPT static void MaybeFireNodeRemoved(nsINode* aChild,
+                                                      nsINode* aParent);
+
+  /**
+   * These methods create and dispatch a trusted event.
+   * Works only with events which can be created by calling
+   * Document::CreateEvent() with parameter "Events".
+   * Note that don't use these methods for "input" event.  Use
+   * DispatchInputEvent() instead.
+   *
+   * @param aDoc           The document which will be used to create the event.
+   * @param aTarget        The target of the event, should be QIable to
+   *                       EventTarget.
+   * @param aEventName     The name of the event.
+   * @param aCanBubble     Whether the event can bubble.
+   * @param aCancelable    Is the event cancelable.
+   * @param aCopmosed      Is the event composed.
+   * @param aDefaultAction Set to true if default action should be taken,
+   *                       see EventTarget::DispatchEvent.
+   */
+  // TODO: annotate with `MOZ_CAN_RUN_SCRIPT`
+  // (https://bugzilla.mozilla.org/show_bug.cgi?id=1625902).
+  static nsresult DispatchTrustedEvent(Document* aDoc, nsISupports* aTarget,
+                                       const nsAString& aEventName, CanBubble,
+                                       Cancelable,
+                                       Composed aComposed = Composed::eDefault,
+                                       bool* aDefaultAction = nullptr);
+
+  // TODO: annotate with `MOZ_CAN_RUN_SCRIPT`
+  // (https://bugzilla.mozilla.org/show_bug.cgi?id=1625902).
+  static nsresult DispatchTrustedEvent(Document* aDoc, nsISupports* aTarget,
+                                       const nsAString& aEventName,
+                                       CanBubble aCanBubble,
+                                       Cancelable aCancelable,
+                                       bool* aDefaultAction) {
+    return DispatchTrustedEvent(aDoc, aTarget, aEventName, aCanBubble,
+                                aCancelable, Composed::eDefault,
+                                aDefaultAction);
+  }
+
+  /**
+   * This method creates and dispatches a trusted event using an event message.
+   * @param aDoc           The document which will be used to create the event.
+   * @param aTarget        The target of the event, should be QIable to
+   *                       EventTarget.
+   * @param aEventMessage  The event message.
+   * @param aCanBubble     Whether the event can bubble.
+   * @param aCancelable    Is the event cancelable.
+   * @param aDefaultAction Set to true if default action should be taken,
+   *                       see EventTarget::DispatchEvent.
+   */
+  template <class WidgetEventType>
+  static nsresult DispatchTrustedEvent(
+      Document* aDoc, nsISupports* aTarget, EventMessage aEventMessage,
+      CanBubble aCanBubble, Cancelable aCancelable,
+      bool* aDefaultAction = nullptr,
+      ChromeOnlyDispatch aOnlyChromeDispatch = ChromeOnlyDispatch::eNo) {
+    WidgetEventType event(true, aEventMessage);
+    MOZ_ASSERT(GetEventClassIDFromMessage(aEventMessage) == event.mClass);
+    return DispatchEvent(aDoc, aTarget, event, aEventMessage, aCanBubble,
+                         aCancelable, Trusted::eYes, aDefaultAction,
+                         aOnlyChromeDispatch);
+  }
+
+  /**
+   * This method dispatches "beforeinput" event with EditorInputEvent or
+   * "input" event with proper event class.  If it's unsafe to dispatch,
+   * this put the event into the script runner queue.  In such case, the
+   * event becomes not cancelable even if it's defined as cancelable by
+   * the spec.
+   * Input Events spec defines as:
+   *   Input events are dispatched on elements that act as editing hosts,
+   *   including elements with the contenteditable attribute set, textarea
+   *   elements, and input elements that permit text input.
+   *
+   * @param aEventTarget        The event target element of the "beforeinput"
+   *                            or "input" event.  Must not be nullptr.
+   * @param aEventMessage       Muse be eEditorBeforeInput or eEditorInput.
+   * @param aEditorInputType    The inputType value of InputEvent.
+   *                            If aEventTarget won't dispatch "input" event
+   *                            with InputEvent, set EditorInputType::eUnknown.
+   * @param aEditorBase         Optional.  If this is called by editor,
+   *                            editor should set this.  Otherwise, leave
+   *                            nullptr.
+   * @param aOptions            Optional.  If aEditorInputType value requires
+   *                            some additional data, they should be properly
+   *                            set with this argument.
+   * @param aEventStatus        Returns nsEventStatus_eConsumeNoDefault if
+   *                            the dispatching event is cancelable and the
+   *                            event was canceled by script (including
+   *                            chrome script).  Otherwise, returns given
+   *                            value.  Note that this can be nullptr only
+   *                            when the dispatching event is not cancelable.
+   */
+  MOZ_CAN_RUN_SCRIPT static nsresult DispatchInputEvent(Element* aEventTarget);
+  MOZ_CAN_RUN_SCRIPT static nsresult DispatchInputEvent(
+      Element* aEventTarget, mozilla::EventMessage aEventMessage,
+      mozilla::EditorInputType aEditorInputType,
+      mozilla::EditorBase* aEditorBase, mozilla::InputEventOptions&& aOptions,
+      nsEventStatus* aEventStatus = nullptr);
+
+  /**
+   * This method creates and dispatches a untrusted event.
+   * Works only with events which can be created by calling
+   * Document::CreateEvent() with parameter "Events".
+   * @param aDoc           The document which will be used to create the event.
+   * @param aTarget        The target of the event, should be QIable to
+   *                       EventTarget.
+   * @param aEventName     The name of the event.
+   * @param aCanBubble     Whether the event can bubble.
+   * @param aCancelable    Is the event cancelable.
+   * @param aDefaultAction Set to true if default action should be taken,
+   *                       see EventTarget::DispatchEvent.
+   */
+  static nsresult DispatchUntrustedEvent(Document* aDoc, nsISupports* aTarget,
+                                         const nsAString& aEventName, CanBubble,
+                                         Cancelable,
+                                         bool* aDefaultAction = nullptr);
+
+  /**
+   * This method creates and dispatches a untrusted event using an event
+   * message.
+   * @param aDoc           The document which will be used to create the event.
+   * @param aTarget        The target of the event, should be QIable to
+   *                       EventTarget.
+   * @param aEventMessage  The event message.
+   * @param aCanBubble     Whether the event can bubble.
+   * @param aCancelable    Is the event cancelable.
+   * @param aDefaultAction Set to true if default action should be taken,
+   *                       see EventTarget::DispatchEvent.
+   */
+  template <class WidgetEventType>
+  static nsresult DispatchUntrustedEvent(
+      Document* aDoc, nsISupports* aTarget, EventMessage aEventMessage,
+      CanBubble aCanBubble, Cancelable aCancelable,
+      bool* aDefaultAction = nullptr,
+      ChromeOnlyDispatch aOnlyChromeDispatch = ChromeOnlyDispatch::eNo) {
+    WidgetEventType event(false, aEventMessage);
+    MOZ_ASSERT(GetEventClassIDFromMessage(aEventMessage) == event.mClass);
+    return DispatchEvent(aDoc, aTarget, event, aEventMessage, aCanBubble,
+                         aCancelable, Trusted::eNo, aDefaultAction,
+                         aOnlyChromeDispatch);
+  }
+
+  /**
+   * This method creates and dispatches a trusted event to the chrome
+   * event handler (the parent object of the DOM Window in the event target
+   * chain). Note, chrome event handler is used even if aTarget is a chrome
+   * object. Use DispatchEventOnlyToChrome if the normal event dispatching is
+   * wanted in case aTarget is a chrome object.
+   * Works only with events which can be created by calling
+   * Document::CreateEvent() with parameter "Events".
+   * @param aDocument      The document which will be used to create the event,
+   *                       and whose window's chrome handler will be used to
+   *                       dispatch the event.
+   * @param aTarget        The target of the event, used for event->SetTarget()
+   * @param aEventName     The name of the event.
+   * @param aCanBubble     Whether the event can bubble.
+   * @param aCancelable    Is the event cancelable.
+   * @param aDefaultAction Set to true if default action should be taken,
+   *                       see EventTarget::DispatchEvent.
+   */
+  static nsresult DispatchChromeEvent(Document* aDoc, nsISupports* aTarget,
+                                      const nsAString& aEventName, CanBubble,
+                                      Cancelable,
+                                      bool* aDefaultAction = nullptr);
+
+  /**
+   * Helper to dispatch a "framefocusrequested" event to chrome, which will only
+   * bring the window to the foreground and switch tabs if aCanRaise is true.
+   */
+  MOZ_CAN_RUN_SCRIPT_BOUNDARY static void RequestFrameFocus(
+      Element& aFrameElement, bool aCanRaise,
+      mozilla::dom::CallerType aCallerType);
+
+  /**
+   * This method creates and dispatches a trusted event.
+   * If aTarget is not a chrome object, the nearest chrome object in the
+   * propagation path will be used as the start of the event target chain.
+   * This method is different than DispatchChromeEvent, which always dispatches
+   * events to chrome event handler. DispatchEventOnlyToChrome works like
+   * DispatchTrustedEvent in the case aTarget is a chrome object.
+   * Works only with events which can be created by calling
+   * Document::CreateEvent() with parameter "Events".
+   * @param aDoc           The document which will be used to create the event.
+   * @param aTarget        The target of the event, should be QIable to
+   *                       EventTarget.
+   * @param aEventName     The name of the event.
+   * @param aCanBubble     Whether the event can bubble.
+   * @param aCancelable    Is the event cancelable.
+   * @param aComposed      Is the event composed.
+   * @param aDefaultAction Set to true if default action should be taken,
+   *                       see EventTarget::DispatchEvent.
+   */
+  static nsresult DispatchEventOnlyToChrome(
+      Document* aDoc, nsISupports* aTarget, const nsAString& aEventName,
+      CanBubble, Cancelable, Composed aComposed = Composed::eDefault,
+      bool* aDefaultAction = nullptr);
+
+  static nsresult DispatchEventOnlyToChrome(
+      Document* aDoc, nsISupports* aTarget, const nsAString& aEventName,
+      CanBubble aCanBubble, Cancelable aCancelable, bool* aDefaultAction) {
+    return DispatchEventOnlyToChrome(aDoc, aTarget, aEventName, aCanBubble,
+                                     aCancelable, Composed::eDefault,
+                                     aDefaultAction);
+  }
+
+  /**
+   * Determines if an event attribute name (such as onclick) is valid for
+   * a given element type. Types are from the EventNameType enumeration
+   * defined above.
+   *
+   * @param aName the event name to look up
+   * @param aType the type of content
+   */
+  static bool IsEventAttributeName(nsAtom* aName, int32_t aType);
+
+  /**
+   * Return the event message for the event with the given name. The name is
+   * the event name with the 'on' prefix. Returns eUnidentifiedEvent if the
+   * event doesn't match a known event name.
+   *
+   * @param aName the event name to look up
+   */
+  static EventMessage GetEventMessage(nsAtom* aName);
+
+  /**
+   * Returns the EventMessage and nsAtom to be used for event listener
+   * registration.
+   */
+  static EventMessage GetEventMessageAndAtomForListener(const nsAString& aName,
+                                                        nsAtom** aOnName);
+
+  /**
+   * Return the EventClassID for the event with the given name. The name is the
+   * event name *without* the 'on' prefix. Returns eBasicEventClass if the event
+   * is not known to be of any particular event class.
+   *
+   * @param aName the event name to look up
+   */
+  static mozilla::EventClassID GetEventClassID(const nsAString& aName);
+
+  /**
+   * Return the event message and atom for the event with the given name.
+   * The name is the event name *without* the 'on' prefix.
+   * Returns eUnidentifiedEvent on the aEventID if the
+   * event doesn't match a known event name in the category.
+   *
+   * @param aName the event name to look up
+   * @param aEventClassID only return event id for aEventClassID
+   */
+  static nsAtom* GetEventMessageAndAtom(const nsAString& aName,
+                                        mozilla::EventClassID aEventClassID,
+                                        EventMessage* aEventMessage);
+
+  /**
+   * Used only during traversal of the XPCOM graph by the cycle
+   * collector: push a pointer to the listener manager onto the
+   * children deque, if it exists. Do nothing if there is no listener
+   * manager.
+   *
+   * Crucially: does not perform any refcounting operations.
+   *
+   * @param aNode The node to traverse.
+   * @param children The buffer to push a listener manager pointer into.
+   */
+  static void TraverseListenerManager(nsINode* aNode,
+                                      nsCycleCollectionTraversalCallback& cb);
+
+  /**
+   * Get the eventlistener manager for aNode, creating it if it does not
+   * already exist.
+   *
+   * @param aNode The node for which to get the eventlistener manager.
+   */
+  static mozilla::EventListenerManager* GetListenerManagerForNode(
+      nsINode* aNode);
+  /**
+   * Get the eventlistener manager for aNode, returning null if it does not
+   * already exist.
+   *
+   * @param aNode The node for which to get the eventlistener manager.
+   */
+  static mozilla::EventListenerManager* GetExistingListenerManagerForNode(
+      const nsINode* aNode);
+
+  static void AddEntryToDOMArenaTable(nsINode* aNode,
+                                      mozilla::dom::DOMArena* aDOMArena);
+
+  static already_AddRefed<mozilla::dom::DOMArena> TakeEntryFromDOMArenaTable(
+      const nsINode* aNode);
+
+  static void UnmarkGrayJSListenersInCCGenerationDocuments();
+
+  /**
+   * Remove the eventlistener manager for aNode.
+   *
+   * @param aNode The node for which to remove the eventlistener manager.
+   */
+  static void RemoveListenerManager(nsINode* aNode);
+
+  static bool IsInitialized() { return sInitialized; }
+
+  /**
+   * Checks if the localname/prefix/namespace triple is valid wrt prefix
+   * and namespace according to the Namespaces in XML and DOM Code
+   * specfications.
+   *
+   * @param aLocalname localname of the node
+   * @param aPrefix prefix of the node
+   * @param aNamespaceID namespace of the node
+   */
+  static bool IsValidNodeName(nsAtom* aLocalName, nsAtom* aPrefix,
+                              int32_t aNamespaceID);
+
+  /**
+   * Creates a DocumentFragment from text using a context node to resolve
+   * namespaces.
+   *
+   * Please note that for safety reasons, if the node principal of
+   * aContextNode is the system principal, this function will automatically
+   * sanitize its input using nsTreeSanitizer.
+   *
+   * Note! In the HTML case with the HTML5 parser enabled, this is only called
+   * from Range.createContextualFragment() and the implementation here is
+   * quirky accordingly (html context node behaves like a body context node).
+   * If you don't want that quirky behavior, don't use this method as-is!
+   *
+   * @param aContextNode the node which is used to resolve namespaces
+   * @param aFragment the string which is parsed to a DocumentFragment
+   * @param aReturn the resulting fragment
+   * @param aPreventScriptExecution whether to mark scripts as already started
+   */
+  static already_AddRefed<mozilla::dom::DocumentFragment>
+  CreateContextualFragment(nsINode* aContextNode, const nsAString& aFragment,
+                           bool aPreventScriptExecution,
+                           mozilla::ErrorResult& aRv);
+
+  /**
+   * Invoke the fragment parsing algorithm (innerHTML) using the HTML parser.
+   *
+   * Please note that for safety reasons, if the node principal of aTargetNode
+   * is the system principal, this function will automatically sanitize its
+   * input using nsTreeSanitizer.
+   *
+   * @param aSourceBuffer the string being set as innerHTML
+   * @param aTargetNode the target container
+   * @param aContextLocalName local name of context node
+   * @param aContextNamespace namespace of context node
+   * @param aQuirks true to make <table> not close <p>
+   * @param aPreventScriptExecution true to prevent scripts from executing;
+   *        don't set to false when parsing into a target node that has been
+   *        bound to tree.
+   * @return NS_ERROR_DOM_INVALID_STATE_ERR if a re-entrant attempt to parse
+   *         fragments is made, NS_ERROR_OUT_OF_MEMORY if aSourceBuffer is too
+   *         long and NS_OK otherwise.
+   * @param aFlags defaults to -1 indicating that ParseFragmentHTML will do
+   *        default sanitization for system privileged calls to it. Only
+   *        ParserUtils::ParseFragment() should ever pass explicit aFlags
+   *        which will then used for sanitization of the fragment.
+   *        To pass explicit aFlags use any of the sanitization flags
+   *        listed in nsIParserUtils.idl.
+   */
+  static nsresult ParseFragmentHTML(const nsAString& aSourceBuffer,
+                                    nsIContent* aTargetNode,
+                                    nsAtom* aContextLocalName,
+                                    int32_t aContextNamespace, bool aQuirks,
+                                    bool aPreventScriptExecution,
+                                    int32_t aFlags = -1);
+
+  /**
+   * Invoke the fragment parsing algorithm (innerHTML) using the XML parser.
+   *
+   * Please note that for safety reasons, if the node principal of aDocument
+   * is the system principal, this function will automatically sanitize its
+   * input using nsTreeSanitizer.
+   *
+   * @param aSourceBuffer the string being set as innerHTML
+   * @param aDocument the target document
+   * @param aTagStack the namespace mapping context
+   * @param aPreventExecution whether to mark scripts as already started
+   * @param aFlags, pass -1 and ParseFragmentXML will do default
+   *        sanitization for system privileged calls to it. Only
+   *        ParserUtils::ParseFragment() should ever pass explicit aFlags
+   *        which will then used for sanitization of the fragment.
+   *        To pass explicit aFlags use any of the sanitization flags
+   *        listed in nsIParserUtils.idl.
+   * @param aReturn the result fragment
+   * @return NS_ERROR_DOM_INVALID_STATE_ERR if a re-entrant attempt to parse
+   *         fragments is made, a return code from the XML parser.
+   */
+  static nsresult ParseFragmentXML(const nsAString& aSourceBuffer,
+                                   Document* aDocument,
+                                   nsTArray<nsString>& aTagStack,
+                                   bool aPreventScriptExecution, int32_t aFlags,
+                                   mozilla::dom::DocumentFragment** aReturn);
+
+  /**
+   * Parse a string into a document using the HTML parser.
+   * Script elements are marked unexecutable.
+   *
+   * @param aSourceBuffer the string to parse as an HTML document
+   * @param aTargetDocument the document object to parse into. Must not have
+   *                        child nodes.
+   * @param aScriptingEnabledForNoscriptParsing whether <noscript> is parsed
+   *                                            as if scripting was enabled
+   * @return NS_ERROR_DOM_INVALID_STATE_ERR if a re-entrant attempt to parse
+   *         fragments is made, NS_ERROR_OUT_OF_MEMORY if aSourceBuffer is too
+   *         long and NS_OK otherwise.
+   */
+  static nsresult ParseDocumentHTML(const nsAString& aSourceBuffer,
+                                    Document* aTargetDocument,
+                                    bool aScriptingEnabledForNoscriptParsing);
+
+  /**
+   * Converts HTML source to plain text by parsing the source and using the
+   * plain text serializer on the resulting tree.
+   *
+   * @param aSourceBuffer the string to parse as an HTML document
+   * @param aResultBuffer the string where the plain text result appears;
+   *                      may be the same string as aSourceBuffer
+   * @param aFlags Flags from nsIDocumentEncoder.
+   * @param aWrapCol Number of columns after which to line wrap; 0 for no
+   *                 auto-wrapping
+   * @return NS_ERROR_DOM_INVALID_STATE_ERR if a re-entrant attempt to parse
+   *         fragments is made, NS_ERROR_OUT_OF_MEMORY if aSourceBuffer is too
+   *         long and NS_OK otherwise.
+   */
+  static nsresult ConvertToPlainText(const nsAString& aSourceBuffer,
+                                     nsAString& aResultBuffer, uint32_t aFlags,
+                                     uint32_t aWrapCol);
+
+  /**
+   * Creates a 'loaded-as-data' HTML document that takes that principal,
+   * script global, and URL from the argument, which may be null.
+   */
+  static already_AddRefed<Document> CreateInertHTMLDocument(
+      const Document* aTemplate);
+
+  /**
+   * Creates a 'loaded-as-data' XML document that takes that principal,
+   * script global, and URL from the argument, which may be null.
+   */
+  static already_AddRefed<Document> CreateInertXMLDocument(
+      const Document* aTemplate);
+
+ public:
+  /**
+   * Sets the text contents of a node by replacing all existing children
+   * with a single text child.
+   *
+   * The function always notifies.
+   *
+   * Will reuse the first text child if one is available. Will not reuse
+   * existing cdata children.
+   *
+   * TODO: Convert this to MOZ_CAN_RUN_SCRIPT (bug 1415230)
+   *
+   * @param aContent Node to set contents of.
+   * @param aValue   Value to set contents to.
+   * @param aTryReuse When true, the function will try to reuse an existing
+   *                  textnodes rather than always creating a new one.
+   */
+  MOZ_CAN_RUN_SCRIPT_BOUNDARY static nsresult SetNodeTextContent(
+      nsIContent* aContent, const nsAString& aValue, bool aTryReuse);
+
+  /**
+   * Get the textual contents of a node. This is a concatenation of all
+   * textnodes that are direct or (depending on aDeep) indirect children
+   * of the node.
+   *
+   * NOTE! No serialization takes place and <br> elements
+   * are not converted into newlines. Only textnodes and cdata nodes are
+   * added to the result.
+   *
+   * @see nsLayoutUtils::GetFrameTextContent
+   *
+   * @param aNode Node to get textual contents of.
+   * @param aDeep If true child elements of aNode are recursivly descended
+   *              into to find text children.
+   * @param aResult the result. Out param.
+   * @return false on out of memory errors, true otherwise.
+   */
+  [[nodiscard]] static bool GetNodeTextContent(const nsINode* aNode, bool aDeep,
+                                               nsAString& aResult,
+                                               const mozilla::fallible_t&);
+
+  static void GetNodeTextContent(const nsINode* aNode, bool aDeep,
+                                 nsAString& aResult);
+
+  /**
+   * Same as GetNodeTextContents but appends the result rather than sets it.
+   */
+  static bool AppendNodeTextContent(const nsINode* aNode, bool aDeep,
+                                    nsAString& aResult,
+                                    const mozilla::fallible_t&);
+
+  /**
+   * Utility method that checks if a given node has any non-empty children. This
+   * method does not descend recursively into children by default.
+   *
+   * @param aDiscoverMode Set to eRecurseIntoChildren to descend recursively
+   * into children.
+   */
+  enum TextContentDiscoverMode : uint8_t {
+    eRecurseIntoChildren,
+    eDontRecurseIntoChildren
+  };
+
+  static bool HasNonEmptyTextContent(
+      nsINode* aNode,
+      TextContentDiscoverMode aDiscoverMode = eDontRecurseIntoChildren);
+
+  /**
+   * Delete strings allocated for nsContentList matches
+   */
+  static void DestroyMatchString(void* aData);
+
+  /*
+   * Notify when the first XUL menu is opened and when the all XUL menus are
+   * closed. At opening, aInstalling should be TRUE, otherwise, it should be
+   * FALSE.
+   */
+  MOZ_CAN_RUN_SCRIPT static void NotifyInstalledMenuKeyboardListener(
+      bool aInstalling);
+
+  /**
+   * Check whether the nsIURI uses the given scheme.
+   *
+   * Note that this will check the innermost URI rather than that of
+   * the nsIURI itself.
+   */
+  static bool SchemeIs(nsIURI* aURI, const char* aScheme);
+
+  /**
+   * Returns true if aPrincipal is an ExpandedPrincipal.
+   */
+  static bool IsExpandedPrincipal(nsIPrincipal* aPrincipal);
+
+  /**
+   * Returns true if aPrincipal is the system or an ExpandedPrincipal.
+   */
+  static bool IsSystemOrExpandedPrincipal(nsIPrincipal* aPrincipal);
+
+  /**
+   * Gets the system principal from the security manager.
+   */
+  static nsIPrincipal* GetSystemPrincipal();
+
+  /**
+   * Gets the null subject principal singleton. This is only useful for
+   * assertions.
+   */
+  static nsIPrincipal* GetNullSubjectPrincipal() {
+    return sNullSubjectPrincipal;
+  }
+
+  /**
+   * *aResourcePrincipal is a principal describing who may access the contents
+   * of a resource. The resource can only be consumed by a principal that
+   * subsumes *aResourcePrincipal. MAKE SURE THAT NOTHING EVER ACTS WITH THE
+   * AUTHORITY OF *aResourcePrincipal.
+   * It may be null to indicate that the resource has no data from any origin
+   * in it yet and anything may access the resource.
+   * Additional data is being mixed into the resource from aExtraPrincipal
+   * (which may be null; if null, no data is being mixed in and this function
+   * will do nothing). Update *aResourcePrincipal to reflect the new data.
+   * If *aResourcePrincipal subsumes aExtraPrincipal, nothing needs to change,
+   * otherwise *aResourcePrincipal is replaced with the system principal.
+   * Returns true if *aResourcePrincipal changed.
+   */
+  static bool CombineResourcePrincipals(
+      nsCOMPtr<nsIPrincipal>* aResourcePrincipal,
+      nsIPrincipal* aExtraPrincipal);
+
+  /**
+   * Trigger a link with uri aLinkURI. If aClick is false, this triggers a
+   * mouseover on the link, otherwise it triggers a load after doing a
+   * security check using aContent's principal.
+   *
+   * @param aContent the node on which a link was triggered.
+   * @param aLinkURI the URI of the link, must be non-null.
+   * @param aTargetSpec the target (like target=, may be empty).
+   * @param aClick whether this was a click or not (if false, this method
+   *               assumes you just hovered over the link).
+   * @param aIsTrusted If false, JS Context will be pushed to stack
+   *                   when the link is triggered.
+   */
+  static void TriggerLink(nsIContent* aContent, nsIURI* aLinkURI,
+                          const nsString& aTargetSpec, bool aClick,
+                          bool aIsTrusted);
+
+  /**
+   * Get the link location.
+   */
+  static void GetLinkLocation(mozilla::dom::Element* aElement,
+                              nsString& aLocationString);
+
+  /**
+   * Return top-level widget in the parent chain.
+   */
+  static nsIWidget* GetTopLevelWidget(nsIWidget* aWidget);
+
+  /**
+   * Return the localized ellipsis for UI.
+   */
+  static const nsDependentString GetLocalizedEllipsis();
+
+  /**
+   * Hide any XUL popups associated with aDocument, including any documents
+   * displayed in child frames. Does nothing if aDocument is null.
+   */
+  MOZ_CAN_RUN_SCRIPT_BOUNDARY static void HidePopupsInDocument(
+      Document* aDocument);
+
+  /**
+   * Retrieve the current drag session, or null if no drag is currently occuring
+   */
+  static already_AddRefed<nsIDragSession> GetDragSession();
+
+  /*
+   * Initialize and set the dataTransfer field of an WidgetDragEvent.
+   */
+  static nsresult SetDataTransferInEvent(mozilla::WidgetDragEvent* aDragEvent);
+
+  // filters the drag and drop action to fit within the effects allowed and
+  // returns it.
+  static uint32_t FilterDropEffect(uint32_t aAction, uint32_t aEffectAllowed);
+
+  /*
+   * Return true if the target of a drop event is a content document that is
+   * an ancestor of the document for the source of the drag.
+   */
+  static bool CheckForSubFrameDrop(nsIDragSession* aDragSession,
+                                   mozilla::WidgetDragEvent* aDropEvent);
+
+  /**
+   * Return true if aURI is a local file URI (i.e. file://).
+   */
+  static bool URIIsLocalFile(nsIURI* aURI);
+
+  /**
+   * Get the application manifest URI for this document.  The manifest URI
+   * is specified in the manifest= attribute of the root element of the
+   * document.
+   *
+   * @param aDocument The document that lists the manifest.
+   * @param aURI The manifest URI.
+   */
+  static void GetOfflineAppManifest(Document* aDocument, nsIURI** aURI);
+
+  /**
+   * Check whether an application should be allowed to use offline APIs.
+   */
+  static bool OfflineAppAllowed(nsIURI* aURI);
+
+  /**
+   * Check whether an application should be allowed to use offline APIs.
+   */
+  static bool OfflineAppAllowed(nsIPrincipal* aPrincipal);
+
+  /**
+   * Increases the count of blockers preventing scripts from running.
+   * NOTE: You might want to use nsAutoScriptBlocker rather than calling
+   * this directly
+   */
+  static void AddScriptBlocker();
+
+  /**
+   * Decreases the count of blockers preventing scripts from running.
+   * NOTE: You might want to use nsAutoScriptBlocker rather than calling
+   * this directly
+   *
+   * WARNING! Calling this function could synchronously execute scripts.
+   */
+  static void RemoveScriptBlocker();
+
+  /**
+   * Add a runnable that is to be executed as soon as it's safe to execute
+   * scripts.
+   * NOTE: If it's currently safe to execute scripts, aRunnable will be run
+   *       synchronously before the function returns.
+   *
+   * @param aRunnable  The nsIRunnable to run as soon as it's safe to execute
+   *                   scripts. Passing null is allowed and results in nothing
+   *                   happening. It is also allowed to pass an object that
+   *                   has not yet been AddRefed.
+   */
+  static void AddScriptRunner(already_AddRefed<nsIRunnable> aRunnable);
+  static void AddScriptRunner(nsIRunnable* aRunnable);
+
+  /**
+   * Returns true if it's safe to execute content script and false otherwise.
+   *
+   * The only known case where this lies is mutation events. They run, and can
+   * run anything else, when this function returns false, but this is ok.
+   */
+  static bool IsSafeToRunScript();
+
+  // Returns the browser window with the most recent time stamp that is
+  // not in private browsing mode.
+  static already_AddRefed<nsPIDOMWindowOuter> GetMostRecentNonPBWindow();
+
+  /**
+   * Call this function if !IsSafeToRunScript() and we fail to run the script
+   * (rather than using AddScriptRunner as we usually do). |aDocument| is
+   * optional as it is only used for showing the URL in the console.
+   */
+  static void WarnScriptWasIgnored(Document* aDocument);
+
+  /**
+   * Add a "synchronous section", in the form of an nsIRunnable run once the
+   * event loop has reached a "stable state". |aRunnable| must not cause any
+   * queued events to be processed (i.e. must not spin the event loop).
+   * We've reached a stable state when the currently executing task/event has
+   * finished, see
+   * http://www.whatwg.org/specs/web-apps/current-work/multipage/webappapis.html#synchronous-section
+   * In practice this runs aRunnable once the currently executing event
+   * finishes. If called multiple times per task/event, all the runnables will
+   * be executed, in the order in which RunInStableState() was called.
+   */
+  static void RunInStableState(already_AddRefed<nsIRunnable> aRunnable);
+
+  /* Add a pending IDBTransaction to be cleaned up at the end of performing a
+   * microtask checkpoint.
+   * See the step of "Cleanup Indexed Database Transactions" in
+   * https://html.spec.whatwg.org/multipage/webappapis.html#perform-a-microtask-checkpoint
+   */
+  static void AddPendingIDBTransaction(
+      already_AddRefed<nsIRunnable> aTransaction);
+
+  /**
+   * Returns true if we are doing StableState/MetastableState.
+   */
+  static bool IsInStableOrMetaStableState();
+
+  static JSContext* GetCurrentJSContext();
+
+  /**
+   * Case insensitive comparison between two atoms.
+   */
+  static bool EqualsIgnoreASCIICase(nsAtom* aAtom1, nsAtom* aAtom2);
+
+  /**
+   * Case insensitive comparison between two strings. However it only ignores
+   * case for ASCII characters a-z.
+   */
+  static bool EqualsIgnoreASCIICase(const nsAString& aStr1,
+                                    const nsAString& aStr2);
+
+  /**
+   * Convert ASCII A-Z to a-z.
+   */
+  static void ASCIIToLower(nsAString& aStr);
+  static void ASCIIToLower(nsACString& aStr);
+  static void ASCIIToLower(const nsAString& aSource, nsAString& aDest);
+  static void ASCIIToLower(const nsACString& aSource, nsACString& aDest);
+
+  /**
+   * Convert ASCII a-z to A-Z.
+   */
+  static void ASCIIToUpper(nsAString& aStr);
+  static void ASCIIToUpper(nsACString& aStr);
+  static void ASCIIToUpper(const nsAString& aSource, nsAString& aDest);
+  static void ASCIIToUpper(const nsACString& aSource, nsACString& aDest);
+
+  /**
+   * Return whether aStr contains an ASCII uppercase character.
+   */
+  static bool StringContainsASCIIUpper(const nsAString& aStr);
+
+  // Returns NS_OK for same origin, error (NS_ERROR_DOM_BAD_URI) if not.
+  static nsresult CheckSameOrigin(nsIChannel* aOldChannel,
+                                  nsIChannel* aNewChannel);
+  static nsIInterfaceRequestor* SameOriginChecker();
+
+  /**
+   * Get the Origin of the passed in nsIPrincipal or nsIURI. If the passed in
+   * nsIURI or the URI of the passed in nsIPrincipal does not have a host, the
+   * origin is set to 'null'.
+   *
+   * The ASCII versions return a ASCII strings that are puny-code encoded,
+   * suitable for, for example, header values. The UTF versions return strings
+   * containing international characters.
+   *
+   * The thread-safe versions return NS_ERROR_UNKNOWN_PROTOCOL if the
+   * operation cannot be completed on the current thread.
+   *
+   * @pre aPrincipal/aOrigin must not be null.
+   *
+   * @note this should be used for HTML5 origin determination.
+   */
+  static nsresult GetASCIIOrigin(nsIURI* aURI, nsACString& aOrigin);
+  static nsresult GetUTFOrigin(nsIPrincipal* aPrincipal, nsAString& aOrigin);
+  static nsresult GetUTFOrigin(nsIURI* aURI, nsAString& aOrigin);
+
+  /**
+   * This method creates and dispatches "command" event, which implements
+   * XULCommandEvent.
+   * If aPresShell is not null, dispatching goes via
+   * PresShell::HandleDOMEventWithTarget().
+   */
+  MOZ_CAN_RUN_SCRIPT
+  static nsresult DispatchXULCommand(
+      nsIContent* aTarget, bool aTrusted,
+      mozilla::dom::Event* aSourceEvent = nullptr,
+      mozilla::PresShell* aPresShell = nullptr, bool aCtrl = false,
+      bool aAlt = false, bool aShift = false, bool aMeta = false,
+      // Including MouseEventBinding here leads
+      // to incude loops, unfortunately.
+      uint16_t inputSource = 0 /* MouseEvent_Binding::MOZ_SOURCE_UNKNOWN */,
+      int16_t aButton = 0);
+
+  static bool CheckMayLoad(nsIPrincipal* aPrincipal, nsIChannel* aChannel,
+                           bool aAllowIfInheritsPrincipal);
+
+  /**
+   * The method checks whether the caller can access native anonymous content.
+   * If there is no JS in the stack or privileged JS is running, this
+   * method returns true, otherwise false.
+   */
+  static bool CanAccessNativeAnon();
+
+  [[nodiscard]] static nsresult WrapNative(JSContext* cx, nsISupports* native,
+                                           const nsIID* aIID,
+                                           JS::MutableHandle<JS::Value> vp,
+                                           bool aAllowWrapping = true) {
+    return WrapNative(cx, native, nullptr, aIID, vp, aAllowWrapping);
+  }
+
+  // Same as the WrapNative above, but use this one if aIID is nsISupports' IID.
+  [[nodiscard]] static nsresult WrapNative(JSContext* cx, nsISupports* native,
+                                           JS::MutableHandle<JS::Value> vp,
+                                           bool aAllowWrapping = true) {
+    return WrapNative(cx, native, nullptr, nullptr, vp, aAllowWrapping);
+  }
+
+  [[nodiscard]] static nsresult WrapNative(JSContext* cx, nsISupports* native,
+                                           nsWrapperCache* cache,
+                                           JS::MutableHandle<JS::Value> vp,
+                                           bool aAllowWrapping = true) {
+    return WrapNative(cx, native, cache, nullptr, vp, aAllowWrapping);
+  }
+
+  /**
+   * Creates an arraybuffer from a binary string.
+   */
+  static nsresult CreateArrayBuffer(JSContext* aCx, const nsACString& aData,
+                                    JSObject** aResult);
+
+  static void StripNullChars(const nsAString& aInStr, nsAString& aOutStr);
+
+  /**
+   * Strip all \n, \r and nulls from the given string
+   * @param aString the string to remove newlines from [in/out]
+   */
+  static void RemoveNewlines(nsString& aString);
+
+  /**
+   * Convert Windows and Mac platform linebreaks to \n.
+   * @param aString the string to convert the newlines inside [in/out]
+   */
+  static void PlatformToDOMLineBreaks(nsString& aString);
+  [[nodiscard]] static bool PlatformToDOMLineBreaks(nsString& aString,
+                                                    const mozilla::fallible_t&);
+
+  /**
+   * Populates aResultString with the contents of the string-buffer aBuf, up
+   * to aBuf's null-terminator.  aBuf must not be null. Ownership of the string
+   * is not transferred.
+   */
+  static void PopulateStringFromStringBuffer(nsStringBuffer* aBuf,
+                                             nsAString& aResultString);
+
+  static bool IsHandlingKeyBoardEvent() { return sIsHandlingKeyBoardEvent; }
+
+  static void SetIsHandlingKeyBoardEvent(bool aHandling) {
+    sIsHandlingKeyBoardEvent = aHandling;
+  }
+
+  /**
+   * Utility method for getElementsByClassName.  aRootNode is the node (either
+   * document or element), which getElementsByClassName was called on.
+   */
+  static already_AddRefed<nsContentList> GetElementsByClassName(
+      nsINode* aRootNode, const nsAString& aClasses);
+
+  /**
+   * Returns a presshell for this document, if there is one. This will be
+   * aDoc's direct presshell if there is one, otherwise we'll look at all
+   * ancestor documents to try to find a presshell, so for example this can
+   * still find a presshell for documents in display:none frames that have
+   * no presentation. So you have to be careful how you use this presshell ---
+   * getting generic data like a device context or widget from it is OK, but it
+   * might not be this document's actual presentation.
+   */
+  static mozilla::PresShell* FindPresShellForDocument(
+      const Document* aDocument);
+
+  /**
+   * Like FindPresShellForDocument, but returns the shell's PresContext instead.
+   */
+  static nsPresContext* FindPresContextForDocument(const Document* aDocument);
+
+  /**
+   * Returns the widget for this document if there is one. Looks at all ancestor
+   * documents to try to find a widget, so for example this can still find a
+   * widget for documents in display:none frames that have no presentation.
+   *
+   * You should probably use WidgetForContent() instead of this, unless you have
+   * a good reason to do otherwise.
+   */
+  static nsIWidget* WidgetForDocument(const Document* aDocument);
+
+  /**
+   * Returns the appropriate widget for this element, if there is one. Unlike
+   * WidgetForDocument(), this returns the correct widget for content in popups.
+   *
+   * You should probably use this instead of WidgetForDocument().
+   */
+  static nsIWidget* WidgetForContent(const nsIContent* aContent);
+
+  /**
+   * Returns a window renderer to use for the given document. Basically we
+   * look up the document hierarchy for the first document which has
+   * a presentation with an associated widget, and use that widget's
+   * window renderer.
+   *
+   * You should probably use WindowRendererForContent() instead of this, unless
+   * you have a good reason to do otherwise.
+   *
+   * @param aDoc the document for which to return a window renderer.
+   * @param aAllowRetaining an outparam that states whether the returned
+   * layer manager should be used for retained layers
+   */
+  static mozilla::WindowRenderer* WindowRendererForDocument(
+      const Document* aDoc);
+
+  /**
+   * Returns a window renderer to use for the given content. Unlike
+   * WindowRendererForDocument(), this returns the correct window renderer for
+   * content in popups.
+   *
+   * You should probably use this instead of WindowRendererForDocument().
+   */
+  static mozilla::WindowRenderer* WindowRendererForContent(
+      const nsIContent* aContent);
+
+  /**
+   * Determine whether a content node is focused or not,
+   *
+   * @param aContent the content node to check
+   * @return true if the content node is focused, false otherwise.
+   */
+  static bool IsFocusedContent(const nsIContent* aContent);
+
+  /**
+   * Returns true if calling execCommand with 'cut' or 'copy' arguments is
+   * allowed for the given subject principal. These are only allowed if the user
+   * initiated them (like with a mouse-click or key press).
+   */
+  static bool IsCutCopyAllowed(Document* aDocument,
+                               nsIPrincipal& aSubjectPrincipal);
+
+  /**
+   * Returns true if CSSOM origin check should be skipped for WebDriver
+   * based crawl to be able to collect data from cross-origin CSS style
+   * sheets. This can be enabled by setting environment variable
+   * MOZ_BYPASS_CSSOM_ORIGIN_CHECK.
+   */
+  static bool BypassCSSOMOriginCheck() {
+#ifdef RELEASE_OR_BETA
+    return false;
+#else
+    return sBypassCSSOMOriginCheck;
+#endif
+  }
+
+  /**
+   * Fire mutation events for changes caused by parsing directly into a
+   * context node.
+   *
+   * @param aDoc the document of the node
+   * @param aDest the destination node that got stuff appended to it
+   * @param aOldChildCount the number of children the node had before parsing
+   */
+  static void FireMutationEventsForDirectParsing(Document* aDoc,
+                                                 nsIContent* aDest,
+                                                 int32_t aOldChildCount);
+
+  /**
+   * Returns true if the content is in a document and contains a plugin
+   * which we don't control event dispatch for, i.e. do any plugins in this
+   * doc tree receive key events outside of our control? This always returns
+   * false on MacOSX.
+   */
+  static bool HasPluginWithUncontrolledEventDispatch(nsIContent* aContent);
+
+  /**
+   * Returns the in-process subtree root document in a document hierarchy.
+   * This could be a chrome document.
+   */
+  static Document* GetInProcessSubtreeRootDocument(Document* aDoc) {
+    return const_cast<Document*>(
+        GetInProcessSubtreeRootDocument(const_cast<const Document*>(aDoc)));
+  }
+  static const Document* GetInProcessSubtreeRootDocument(const Document* aDoc);
+
+  static void GetShiftText(nsAString& text);
+  static void GetControlText(nsAString& text);
+  static void GetMetaText(nsAString& text);
+  static void GetOSText(nsAString& text);
+  static void GetAltText(nsAString& text);
+  static void GetModifierSeparatorText(nsAString& text);
+
+  /**
+   * Returns if aContent has the 'scrollgrab' property.
+   * aContent may be null (in this case false is returned).
+   */
+  static bool HasScrollgrab(nsIContent* aContent);
+
+  /**
+   * Flushes the layout tree (recursively)
+   *
+   * @param aWindow the window the flush should start at
+   *
+   */
+  static void FlushLayoutForTree(nsPIDOMWindowOuter* aWindow);
+
+  /**
+   * Returns true if content with the given principal is allowed to use XUL
+   * and XBL and false otherwise.
+   */
+  static bool AllowXULXBLForPrincipal(nsIPrincipal* aPrincipal);
+
+  /**
+   * Perform cleanup that's appropriate for XPCOM shutdown.
+   */
+  static void XPCOMShutdown();
+
+  /**
+   * Checks if internal PDF viewer is enabled.
+   */
+  static bool IsPDFJSEnabled();
+
+  /**
+   * Checks to see whether the given principal is the internal PDF
+   * viewer principal.
+   */
+  static bool IsPDFJS(nsIPrincipal* aPrincipal);
+  /**
+   * Same, but from WebIDL bindings. Checks whether the subject principal is for
+   * the internal PDF viewer or system JS.
+   */
+  static bool IsSystemOrPDFJS(JSContext*, JSObject*);
+
+  /**
+   * Checks if internal SWF player is enabled.
+   */
+  static bool IsSWFPlayerEnabled();
+
+  enum ContentViewerType {
+    TYPE_UNSUPPORTED,
+    TYPE_CONTENT,
+    TYPE_FALLBACK,
+    TYPE_UNKNOWN
+  };
+
+  static already_AddRefed<nsIDocumentLoaderFactory> FindInternalContentViewer(
+      const nsACString& aType, ContentViewerType* aLoaderType = nullptr);
+
+  /**
+   * This helper method returns true if the aPattern pattern matches aValue.
+   * aPattern should not contain leading and trailing slashes (/).
+   * The pattern has to match the entire value not just a subset.
+   * aDocument must be a valid pointer (not null).
+   *
+   * This is following the HTML5 specification:
+   * http://dev.w3.org/html5/spec/forms.html#attr-input-pattern
+   *
+   * WARNING: This method mutates aPattern and aValue!
+   *
+   * @param aValue       the string to check.
+   * @param aPattern     the string defining the pattern.
+   * @param aDocument    the owner document of the element.
+   * @param aHasMultiple whether or not there are multiple values.
+   * @result             whether the given string is matches the pattern, or
+   *                     Nothing() if the pattern couldn't be evaluated.
+   */
+  static mozilla::Maybe<bool> IsPatternMatching(nsAString& aValue,
+                                                nsAString& aPattern,
+                                                const Document* aDocument,
+                                                bool aHasMultiple = false);
+
+  /**
+   * Calling this adds support for
+   * ontouch* event handler DOM attributes.
+   */
+  static void InitializeTouchEventTable();
+
+  /**
+   * Test whether the given URI always inherits a security context
+   * from the document it comes from.
+   */
+  static nsresult URIInheritsSecurityContext(nsIURI* aURI, bool* aResult);
+
+  /**
+   * Called before a channel is created to query whether the new
+   * channel should inherit the principal.
+   *
+   * The argument aLoadingPrincipal must not be null. The argument
+   * aURI must be the URI of the new channel. If aInheritForAboutBlank
+   * is true, then about:blank will be told to inherit the principal.
+   * If aForceInherit is true, the new channel will be told to inherit
+   * the principal no matter what.
+   *
+   * The return value is whether the new channel should inherit
+   * the principal.
+   */
+  static bool ChannelShouldInheritPrincipal(nsIPrincipal* aLoadingPrincipal,
+                                            nsIURI* aURI,
+                                            bool aInheritForAboutBlank,
+                                            bool aForceInherit);
+
+  static nsresult Btoa(const nsAString& aBinaryData,
+                       nsAString& aAsciiBase64String);
+
+  static nsresult Atob(const nsAString& aAsciiString, nsAString& aBinaryData);
+
+  /**
+   * Returns whether the input element passed in parameter has the autocomplete
+   * functionality enabled. It is taking into account the form owner.
+   * NOTE: the caller has to make sure autocomplete makes sense for the
+   * element's type.
+   *
+   * @param aInput the input element to check. NOTE: aInput can't be null.
+   * @return whether the input element has autocomplete enabled.
+   */
+  static bool IsAutocompleteEnabled(mozilla::dom::HTMLInputElement* aInput);
+
+  enum AutocompleteAttrState : uint8_t {
+    eAutocompleteAttrState_Unknown = 1,
+    eAutocompleteAttrState_Invalid,
+    eAutocompleteAttrState_Valid,
+  };
+  /**
+   * Parses the value of the autocomplete attribute into aResult, ensuring it's
+   * composed of valid tokens, otherwise the value "" is used.
+   * Note that this method is used for form fields, not on a <form> itself.
+   *
+   * @return whether aAttr was valid and can be cached.
+   */
+  static AutocompleteAttrState SerializeAutocompleteAttribute(
+      const nsAttrValue* aAttr, nsAString& aResult,
+      AutocompleteAttrState aCachedState = eAutocompleteAttrState_Unknown);
+
+  /* Variation that is used to retrieve a dictionary of the parts of the
+   * autocomplete attribute.
+   *
+   * @return whether aAttr was valid and can be cached.
+   */
+  static AutocompleteAttrState SerializeAutocompleteAttribute(
+      const nsAttrValue* aAttr, mozilla::dom::AutocompleteInfo& aInfo,
+      AutocompleteAttrState aCachedState = eAutocompleteAttrState_Unknown,
+      bool aGrantAllValidValue = false);
+
+  /**
+   * This will parse aSource, to extract the value of the pseudo attribute
+   * with the name specified in aName. See
+   * http://www.w3.org/TR/xml-stylesheet/#NT-StyleSheetPI for the specification
+   * which is used to parse aSource.
+   *
+   * @param aSource the string to parse
+   * @param aName the name of the attribute to get the value for
+   * @param aValue [out] the value for the attribute with name specified in
+   *                     aAttribute. Empty if the attribute isn't present.
+   * @return true     if the attribute exists and was successfully parsed.
+   *         false if the attribute doesn't exist, or has a malformed
+   *                  value, such as an unknown or unterminated entity.
+   */
+  static bool GetPseudoAttributeValue(const nsString& aSource, nsAtom* aName,
+                                      nsAString& aValue);
+
+  /**
+   * Returns true if the language name is a version of JavaScript and
+   * false otherwise
+   */
+  static bool IsJavaScriptLanguage(const nsString& aName);
+
+  static bool IsJavascriptMIMEType(const nsAString& aMIMEType);
+
+  static void SplitMimeType(const nsAString& aValue, nsString& aType,
+                            nsString& aParams);
+
+  /**
+   * Takes a selection, and a text control element (<input> or <textarea>), and
+   * returns the offsets in the text content corresponding to the selection.
+   * The selection's anchor and focus must both be in the root node passed or a
+   * descendant.
+   *
+   * @param aSelection      Selection to check
+   * @param aRoot           Root <input> or <textarea> element
+   * @param aOutStartOffset Output start offset
+   * @param aOutEndOffset   Output end offset
+   */
+  static void GetSelectionInTextControl(mozilla::dom::Selection* aSelection,
+                                        Element* aRoot,
+                                        uint32_t& aOutStartOffset,
+                                        uint32_t& aOutEndOffset);
+
+  /**
+   * Takes a frame for anonymous content within a text control (<input> or
+   * <textarea>), and returns an offset in the text content, adjusted for a
+   * trailing <br> frame.
+   *
+   * @param aOffsetFrame      Frame for the text content in which the offset
+   *                          lies
+   * @param aOffset           Offset as calculated by GetContentOffsetsFromPoint
+   * @param aOutOffset        Output adjusted offset
+   *
+   * @see GetSelectionInTextControl for the original basis of this function.
+   */
+  static int32_t GetAdjustedOffsetInTextControl(nsIFrame* aOffsetFrame,
+                                                int32_t aOffset);
+
+  /**
+   * Returns pointer to HTML editor instance for the aPresContext when there is.
+   * The HTML editor is shared by contenteditable elements or used in
+   * designMode.  When there are no contenteditable elements and the document
+   * is not in designMode, this returns nullptr.
+   */
+  static mozilla::HTMLEditor* GetHTMLEditor(nsPresContext* aPresContext);
+  static mozilla::HTMLEditor* GetHTMLEditor(nsDocShell* aDocShell);
+
+  /**
+   * Returns pointer to a text editor if <input> or <textarea> element is
+   * active element in the document for aPresContext, or pointer to HTML
+   * editor if there is (i.e., even if non-editable element has focus or
+   * nobody has focus).  The reason is, HTML editor may handle some input
+   * even if there is no active editing host.
+   * Note that this does not return editor in descendant documents.
+   */
+  static mozilla::EditorBase* GetActiveEditor(nsPresContext* aPresContext);
+  static mozilla::EditorBase* GetActiveEditor(nsPIDOMWindowOuter* aWindow);
+
+  /**
+   * Returns `TextEditor` which manages `aAnonymousContent` if there is.
+   * Note that this method returns `nullptr` if `TextEditor` for the
+   * `aAnonymousContent` hasn't been created yet.
+   */
+  static mozilla::TextEditor* GetTextEditorFromAnonymousNodeWithoutCreation(
+      const nsIContent* aAnonymousContent);
+
+  /**
+   * Returns whether a node has an editable ancestor.
+   *
+   * @param aNode The node to test.
+   */
+  static bool IsNodeInEditableRegion(nsINode* aNode);
+
+  /**
+   * Returns a LogModule that logs debugging info from RFP functions.
+   */
+  static mozilla::LogModule* ResistFingerprintingLog();
+
+  /**
+   * Returns a LogModule that dump calls from content script are logged to.
+   * This can be enabled with the 'Dump' module, and is useful for synchronizing
+   * content JS to other logging modules.
+   */
+  static mozilla::LogModule* DOMDumpLog();
+
+  /**
+   * Returns whether a given header is forbidden for an XHR or fetch
+   * request.
+   */
+  static bool IsForbiddenRequestHeader(const nsACString& aHeader,
+                                       const nsACString& aValue);
+
+  /**
+   * Returns whether a given header is forbidden for a system XHR
+   * request.
+   */
+  static bool IsForbiddenSystemRequestHeader(const nsACString& aHeader);
+
+  /**
+   * Checks whether the header overrides any http methods
+   */
+  static bool IsOverrideMethodHeader(const nsACString& headerName);
+  /**
+   * Checks whether the  header value contains any forbidden method
+   */
+  static bool ContainsForbiddenMethod(const nsACString& headerValue);
+  /**
+   * Returns whether a given header has characters that aren't permitted
+   */
+  static bool IsCorsUnsafeRequestHeaderValue(const nsACString& aHeaderValue);
+
+  /**
+   * Returns whether a given Accept header value is allowed
+   * for a non-CORS XHR or fetch request.
+   */
+  static bool IsAllowedNonCorsAccept(const nsACString& aHeaderValue);
+
+  /**
+   * Returns whether a given Content-Type header value is allowed
+   * for a non-CORS XHR or fetch request.
+   */
+  static bool IsAllowedNonCorsContentType(const nsACString& aHeaderValue);
+
+  /**
+   * Returns whether a given Content-Language or accept-language header value is
+   * allowed for a non-CORS XHR or fetch request.
+   */
+  static bool IsAllowedNonCorsLanguage(const nsACString& aHeaderValue);
+
+  /**
+   * Returns whether a given header and value is a CORS-safelisted request
+   * header per https://fetch.spec.whatwg.org/#cors-safelisted-request-header
+   */
+  static bool IsCORSSafelistedRequestHeader(const nsACString& aName,
+                                            const nsACString& aValue);
+
+  /**
+   * Returns whether a given header is forbidden for an XHR or fetch
+   * response.
+   */
+  static bool IsForbiddenResponseHeader(const nsACString& aHeader);
+
+  /**
+   * Returns the inner window ID for the window associated with a request.
+   */
+  static uint64_t GetInnerWindowID(nsIRequest* aRequest);
+
+  /**
+   * Returns the inner window ID for the window associated with a load group.
+   */
+  static uint64_t GetInnerWindowID(nsILoadGroup* aLoadGroup);
+
+  /**
+   * Encloses aHost in brackets if it is an IPv6 address.
+   */
+  static void MaybeFixIPv6Host(nsACString& aHost);
+
+  /**
+   * If the hostname for aURI is an IPv6 it encloses it in brackets,
+   * otherwise it just outputs the hostname in aHost.
+   */
+  static nsresult GetHostOrIPv6WithBrackets(nsIURI* aURI, nsAString& aHost);
+  static nsresult GetHostOrIPv6WithBrackets(nsIURI* aURI, nsACString& aHost);
+  static nsresult GetHostOrIPv6WithBrackets(nsIPrincipal* aPrincipal,
+                                            nsACString& aHost);
+
+  /*
+   * Call the given callback on all remote children of the given top-level
+   * window. Return Callstate::Stop from the callback to stop calling further
+   * children.
+   */
+  static void CallOnAllRemoteChildren(
+      nsPIDOMWindowOuter* aWindow,
+      const std::function<mozilla::CallState(mozilla::dom::BrowserParent*)>&
+          aCallback);
+
+  /**
+   * Given an IPCDataTransferImageContainer construct an imgIContainer for the
+   * image encoded by the transfer item.
+   */
+  static nsresult DeserializeTransferableDataImageContainer(
+      const mozilla::dom::IPCTransferableDataImageContainer& aData,
+      imgIContainer** aContainer);
+
+  /**
+   * Given a flavor obtained from an IPCDataTransferItem or nsITransferable,
+   * returns true if we should treat the data as an image.
+   */
+  static bool IsFlavorImage(const nsACString& aFlavor);
+
+  static bool IPCTransferableDataItemHasKnownFlavor(
+      const mozilla::dom::IPCTransferableDataItem& aItem);
+
+  static nsresult IPCTransferableDataToTransferable(
+      const mozilla::dom::IPCTransferableData& aTransferableData,
+      bool aAddDataFlavor, nsITransferable* aTransferable,
+      const bool aFilterUnknownFlavors);
+
+  static nsresult IPCTransferableDataToTransferable(
+      const mozilla::dom::IPCTransferableData& aTransferableData,
+      const bool& aIsPrivateData, nsIPrincipal* aRequestingPrincipal,
+      const nsContentPolicyType& aContentPolicyType, bool aAddDataFlavor,
+      nsITransferable* aTransferable, const bool aFilterUnknownFlavors);
+
+  static nsresult IPCTransferableToTransferable(
+      const mozilla::dom::IPCTransferable& aIPCTransferable,
+      bool aAddDataFlavor, nsITransferable* aTransferable,
+      const bool aFilterUnknownFlavors);
+
+  static nsresult IPCTransferableDataItemToVariant(
+      const mozilla::dom::IPCTransferableDataItem& aItem,
+      nsIWritableVariant* aVariant);
+
+  static void TransferablesToIPCTransferableDatas(
+      nsIArray* aTransferables,
+      nsTArray<mozilla::dom::IPCTransferableData>& aIPC, bool aInSyncMessage,
+      mozilla::dom::ContentParent* aParent);
+
+  static void TransferableToIPCTransferableData(
+      nsITransferable* aTransferable,
+      mozilla::dom::IPCTransferableData* aTransferableData, bool aInSyncMessage,
+      mozilla::dom::ContentParent* aParent);
+
+  static void TransferableToIPCTransferable(
+      nsITransferable* aTransferable,
+      mozilla::dom::IPCTransferable* aIPCTransferable, bool aInSyncMessage,
+      mozilla::dom::ContentParent* aParent);
+
+  /*
+   * Get the pixel data from the given source surface and return it as a
+   * BigBuffer. The length and stride will be assigned from the surface.
+   */
+  static mozilla::Maybe<mozilla::ipc::BigBuffer> GetSurfaceData(
+      mozilla::gfx::DataSourceSurface&, size_t* aLength, int32_t* aStride);
+
+  static mozilla::Maybe<mozilla::dom::IPCImage> SurfaceToIPCImage(
+      mozilla::gfx::DataSourceSurface&);
+  static already_AddRefed<mozilla::gfx::DataSourceSurface> IPCImageToSurface(
+      mozilla::dom::IPCImage&&);
+
+  // Helpers shared by the implementations of nsContentUtils methods and
+  // nsIDOMWindowUtils methods.
+  static mozilla::Modifiers GetWidgetModifiers(int32_t aModifiers);
+  static nsIWidget* GetWidget(mozilla::PresShell* aPresShell, nsPoint* aOffset);
+  static int16_t GetButtonsFlagForButton(int32_t aButton);
+  static mozilla::LayoutDeviceIntPoint ToWidgetPoint(
+      const mozilla::CSSPoint& aPoint, const nsPoint& aOffset,
+      nsPresContext* aPresContext);
+  static nsView* GetViewToDispatchEvent(nsPresContext* aPresContext,
+                                        mozilla::PresShell** aPresShell);
+
+  /**
+   * Synthesize a mouse event to the given widget
+   * (see nsIDOMWindowUtils.sendMouseEvent).
+   */
+  MOZ_CAN_RUN_SCRIPT
+  static nsresult SendMouseEvent(
+      mozilla::PresShell* aPresShell, const nsAString& aType, float aX,
+      float aY, int32_t aButton, int32_t aButtons, int32_t aClickCount,
+      int32_t aModifiers, bool aIgnoreRootScrollFrame, float aPressure,
+      unsigned short aInputSourceArg, uint32_t aIdentifier, bool aToWindow,
+      mozilla::PreventDefaultResult* aPreventDefault,
+      bool aIsDOMEventSynthesized, bool aIsWidgetEventSynthesized);
+
+  static void FirePageShowEventForFrameLoaderSwap(
+      nsIDocShellTreeItem* aItem,
+      mozilla::dom::EventTarget* aChromeEventHandler, bool aFireIfShowing,
+      bool aOnlySystemGroup = false);
+
+  static void FirePageHideEventForFrameLoaderSwap(
+      nsIDocShellTreeItem* aItem,
+      mozilla::dom::EventTarget* aChromeEventHandler,
+      bool aOnlySystemGroup = false);
+
+  static already_AddRefed<nsPIWindowRoot> GetWindowRoot(Document* aDoc);
+
+  /*
+   * If there is a Referrer-Policy response header in |aChannel|, parse a
+   * referrer policy from the header.
+   *
+   * @param the channel from which to get the Referrer-Policy header
+   * @return referrer policy from the response header in aChannel
+   */
+  static mozilla::dom::ReferrerPolicy GetReferrerPolicyFromChannel(
+      nsIChannel* aChannel);
+
+  static bool IsNonSubresourceRequest(nsIChannel* aChannel);
+
+  static bool IsNonSubresourceInternalPolicyType(nsContentPolicyType aType);
+
+ public:
+  /*
+   * Returns true if this window's channel has been marked as a third-party
+   * tracking resource.
+   */
+  static bool IsThirdPartyTrackingResourceWindow(nsPIDOMWindowInner* aWindow);
+
+  /*
+   * Returns true if this window's channel has been marked as a first-party
+   * tracking resource.
+   */
+  static bool IsFirstPartyTrackingResourceWindow(nsPIDOMWindowInner* aWindow);
+
+  /*
+   * Serializes a HTML nsINode into its markup representation.
+   */
+  static bool SerializeNodeToMarkup(nsINode* aRoot, bool aDescendentsOnly,
+                                    nsAString& aOut);
+
+  /*
+   * Returns true iff the provided JSObject is a global, and its URI matches
+   * the provided about: URI.
+   * @param aGlobal the JSObject whose URI to check, if it is a global.
+   * @param aUri the URI to match, e.g. "about:feeds"
+   */
+  static bool IsSpecificAboutPage(JSObject* aGlobal, const char* aUri);
+
+  static void SetScrollbarsVisibility(nsIDocShell* aDocShell, bool aVisible);
+
+  /*
+   * Try to find the docshell corresponding to the given event target.
+   */
+  static nsIDocShell* GetDocShellForEventTarget(
+      mozilla::dom::EventTarget* aTarget);
+
+  /**
+   * Returns true if the "HTTPS state" of the document should be "modern". See:
+   *
+   * https://html.spec.whatwg.org/#concept-document-https-state
+   * https://fetch.spec.whatwg.org/#concept-response-https-state
+   */
+  static bool HttpsStateIsModern(Document* aDocument);
+
+  /**
+   * Returns true if the channel is for top-level window and is over secure
+   * context.
+   * https://github.com/whatwg/html/issues/4930 tracks the spec side of this.
+   */
+  static bool ComputeIsSecureContext(nsIChannel* aChannel);
+
+  /**
+   * Try to upgrade an element.
+   * https://html.spec.whatwg.org/multipage/custom-elements.html#concept-try-upgrade
+   */
+  static void TryToUpgradeElement(Element* aElement);
+
+  /**
+   * Creates a new XUL or XHTML element applying any appropriate custom element
+   * definition.
+   *
+   * If aFromParser != FROM_PARSER_FRAGMENT, a nested event loop permits
+   * arbitrary changes to the world before this function returns.  This should
+   * probably just be MOZ_CAN_RUN_SCRIPT - bug 1543259.
+   */
+  MOZ_CAN_RUN_SCRIPT_BOUNDARY static nsresult NewXULOrHTMLElement(
+      Element** aResult, mozilla::dom::NodeInfo* aNodeInfo,
+      mozilla::dom::FromParser aFromParser, nsAtom* aIsAtom,
+      mozilla::dom::CustomElementDefinition* aDefinition);
+
+  static mozilla::dom::CustomElementRegistry* GetCustomElementRegistry(
+      Document*);
+
+  /**
+   * Looking up a custom element definition.
+   * https://html.spec.whatwg.org/#look-up-a-custom-element-definition
+   */
+  static mozilla::dom::CustomElementDefinition* LookupCustomElementDefinition(
+      Document* aDoc, nsAtom* aNameAtom, uint32_t aNameSpaceID,
+      nsAtom* aTypeAtom);
+
+  static void RegisterCallbackUpgradeElement(Element* aElement,
+                                             nsAtom* aTypeName);
+
+  static void RegisterUnresolvedElement(Element* aElement, nsAtom* aTypeName);
+  static void UnregisterUnresolvedElement(Element* aElement);
+
+  static void EnqueueUpgradeReaction(
+      Element* aElement, mozilla::dom::CustomElementDefinition* aDefinition);
+
+  static void EnqueueLifecycleCallback(
+      mozilla::dom::ElementCallbackType aType, Element* aCustomElement,
+      const mozilla::dom::LifecycleCallbackArgs& aArgs,
+      mozilla::dom::CustomElementDefinition* aDefinition = nullptr);
+
+  /**
+   * Appends all "document level" native anonymous content subtree roots for
+   * aDocument to aElements.  Document level NAC subtrees are those created
+   * by ancestor frames of the document element's primary frame, such as
+   * the scrollbar elements created by the root scroll frame.
+   */
+  static void AppendDocumentLevelNativeAnonymousContentTo(
+      Document* aDocument, nsTArray<nsIContent*>& aElements);
+
+  /**
+   * Appends all native anonymous content subtree roots generated by `aContent`
+   * to `aKids`.
+   *
+   * See `AllChildrenIterator` for the description of the `aFlags` parameter.
+   */
+  static void AppendNativeAnonymousChildren(const nsIContent* aContent,
+                                            nsTArray<nsIContent*>& aKids,
+                                            uint32_t aFlags);
+
+  /**
+   * Query triggeringPrincipal if there's a 'triggeringprincipal' attribute on
+   * aLoadingNode, if no such attribute is specified, aDefaultPrincipal is
+   * returned if it is provided, otherwise the NodePrincipal of aLoadingNode is
+   * returned.
+   *
+   * Return true if aLoadingNode has a 'triggeringprincipal' attribute, and
+   * the value 'triggeringprincipal' is also successfully deserialized,
+   * otherwise return false.
+   */
+  static bool QueryTriggeringPrincipal(nsIContent* aLoadingNode,
+                                       nsIPrincipal* aDefaultPrincipal,
+                                       nsIPrincipal** aTriggeringPrincipal);
+
+  static bool QueryTriggeringPrincipal(nsIContent* aLoadingNode,
+                                       nsIPrincipal** aTriggeringPrincipal) {
+    return QueryTriggeringPrincipal(aLoadingNode, nullptr,
+                                    aTriggeringPrincipal);
+  }
+
+  // Returns whether the image for the given URI and triggering principal is
+  // already available. Ideally this should exactly match the "list of available
+  // images" in the HTML spec, but our implementation of that at best only
+  // resembles it.
+  static bool IsImageAvailable(nsIContent*, nsIURI*,
+                               nsIPrincipal* aDefaultTriggeringPrincipal,
+                               mozilla::CORSMode);
+  static bool IsImageAvailable(nsIURI*, nsIPrincipal* aTriggeringPrincipal,
+                               mozilla::CORSMode, Document*);
+
+  /**
+   * Returns the content policy type that should be used for loading images
+   * for displaying in the UI.  The sources of such images can be <xul:image>,
+   * <xul:menuitem> on OSX where we load the image through nsMenuItemIconX, etc.
+   */
+  static void GetContentPolicyTypeForUIImageLoading(
+      nsIContent* aLoadingNode, nsIPrincipal** aTriggeringPrincipal,
+      nsContentPolicyType& aContentPolicyType, uint64_t* aRequestContextID);
+
+  static nsresult CreateJSValueFromSequenceOfObject(
+      JSContext* aCx, const mozilla::dom::Sequence<JSObject*>& aTransfer,
+      JS::MutableHandle<JS::Value> aValue);
+
+  /**
+   * This implements the structured cloning algorithm as described by
+   * https://html.spec.whatwg.org/#structured-cloning.
+   */
+  static void StructuredClone(
+      JSContext* aCx, nsIGlobalObject* aGlobal, JS::Handle<JS::Value> aValue,
+      const mozilla::dom::StructuredSerializeOptions& aOptions,
+      JS::MutableHandle<JS::Value> aRetval, mozilla::ErrorResult& aError);
+
+  /**
+   * Returns true if reserved key events should be prevented from being sent
+   * to their target. Instead, the key event should be handled by chrome only.
+   */
+  static bool ShouldBlockReservedKeys(mozilla::WidgetKeyboardEvent* aKeyEvent);
+
+  /**
+   * Returns the nsIPluginTag for the plugin we should try to use for a given
+   * MIME type.
+   *
+   * @param aMIMEType  The MIME type of the document being loaded.
+   * @param aNoFakePlugin  If false then this method should consider JS plugins.
+   */
+  static already_AddRefed<nsIPluginTag> PluginTagForType(
+      const nsCString& aMIMEType, bool aNoFakePlugin);
+
+  /**
+   * Returns one of the nsIObjectLoadingContent::TYPE_ values describing the
+   * content type which will be used for the given MIME type when loaded within
+   * an nsObjectLoadingContent.
+   *
+   * NOTE: This method doesn't take capabilities into account. The caller must
+   * take that into account.
+   *
+   * @param aMIMEType  The MIME type of the document being loaded.
+   * @param aNoFakePlugin  If false then this method should consider JS plugins.
+   */
+  static uint32_t HtmlObjectContentTypeForMIMEType(const nsCString& aMIMEType,
+                                                   bool aNoFakePlugin);
+
+  static already_AddRefed<nsISerialEventTarget> GetEventTargetByLoadInfo(
+      nsILoadInfo* aLoadInfo, mozilla::TaskCategory aCategory);
+
+  /**
+   * Detect whether a string is a local-url.
+   * https://drafts.csswg.org/css-values/#local-urls
+   */
+  static bool IsLocalRefURL(const nsAString& aString);
+
+  /**
+   * Compose a tab id with process id and a serial number.
+   */
+  static uint64_t GenerateTabId();
+
+  /**
+   * Compose a browser id with process id and a serial number.
+   */
+  static uint64_t GenerateBrowserId();
+
+  /**
+   * Generate an id for a BrowsingContext using a range of serial
+   * numbers reserved for the current process.
+   */
+  static uint64_t GenerateBrowsingContextId();
+
+  /**
+   * Generate an id using a range of serial numbers reserved for the current
+   * process. aId should be a counter that's incremented every time
+   * GenerateProcessSpecificId is called.
+   */
+  static uint64_t GenerateProcessSpecificId(uint64_t aId);
+
+  static std::tuple<uint64_t, uint64_t> SplitProcessSpecificId(uint64_t aId);
+
+  /**
+   * Generate a window ID which is unique across processes and will never be
+   * recycled.
+   */
+  static uint64_t GenerateWindowId();
+
+  /**
+   * Generate an ID for a load which is unique across processes and will never
+   * be recycled.
+   */
+  static uint64_t GenerateLoadIdentifier();
+
+  /**
+   * Determine whether or not the user is currently interacting with the web
+   * browser. This method is safe to call from off of the main thread.
+   */
+  static bool GetUserIsInteracting();
+
+  // Alternate data MIME type used by the ScriptLoader to register and read
+  // bytecode out of the nsCacheInfoChannel.
+  [[nodiscard]] static bool InitJSBytecodeMimeType();
+  static nsCString& JSScriptBytecodeMimeType() {
+    MOZ_ASSERT(sJSScriptBytecodeMimeType);
+    return *sJSScriptBytecodeMimeType;
+  }
+  static nsCString& JSModuleBytecodeMimeType() {
+    MOZ_ASSERT(sJSModuleBytecodeMimeType);
+    return *sJSModuleBytecodeMimeType;
+  }
+
+  /**
+   * Checks if the passed-in name is one of the special names: "_blank", "_top",
+   * "_parent" or "_self".
+   */
+  static bool IsSpecialName(const nsAString& aName);
+
+  /**
+   * Checks if the passed-in name should override an existing name on the
+   * window. Values which should not override include: "", "_blank", "_top",
+   * "_parent" and "_self".
+   */
+  static bool IsOverridingWindowName(const nsAString& aName);
+
+  /**
+   * If there is a SourceMap (higher precedence) or X-SourceMap (lower
+   * precedence) response header in |aChannel|, set |aResult| to the
+   * header's value and return true.  Otherwise, return false.
+   *
+   * @param aChannel The HTTP channel
+   * @param aResult The string result.
+   */
+  static bool GetSourceMapURL(nsIHttpChannel* aChannel, nsACString& aResult);
+
+  /**
+   * Returns true if the passed-in mesasge is a pending InputEvent.
+   *
+   * @param aMsg  The message to check
+   */
+  static bool IsMessageInputEvent(const IPC::Message& aMsg);
+
+  /**
+   * Returns true if the passed-in message is a critical InputEvent.
+   *
+   * @param aMsg  The message to check
+   */
+  static bool IsMessageCriticalInputEvent(const IPC::Message& aMsg);
+
+  static void AsyncPrecreateStringBundles();
+
+  static bool ContentIsLink(nsIContent* aContent);
+
+  static already_AddRefed<mozilla::dom::ContentFrameMessageManager>
+  TryGetBrowserChildGlobal(nsISupports* aFrom);
+
+  // Get a serial number for a newly created inner or outer window.
+  static uint32_t InnerOrOuterWindowCreated();
+  // Record that an inner or outer window has been destroyed.
+  static void InnerOrOuterWindowDestroyed();
+  // Get the current number of inner or outer windows.
+  static int32_t GetCurrentInnerOrOuterWindowCount() {
+    return sInnerOrOuterWindowCount;
+  }
+
+  // Return an anonymized URI so that it can be safely exposed publicly.
+  static nsresult AnonymizeURI(nsIURI* aURI, nsCString& aAnonymizedURI);
+
+  /**
+   * Serializes a JSON-like JS::Value into a string.
+   * Cases where JSON.stringify would return undefined are handled according to
+   * the |aBehavior| argument:
+   *
+   * - If it is |UndefinedIsNullStringLiteral|, the string "null" is returned.
+   * - If it is |UndefinedIsVoidString|, the void string is returned.
+   *
+   * The |UndefinedIsNullStringLiteral| case is likely not desirable, but is
+   * retained for now for historical reasons.
+   * Usage:
+   *   nsAutoString serializedValue;
+   *   nsContentUtils::StringifyJSON(cx, value, serializedValue, behavior);
+   */
+  static bool StringifyJSON(JSContext* aCx, JS::Handle<JS::Value> aValue,
+                            nsAString& aOutStr, JSONBehavior aBehavior);
+
+  /**
+   * Returns true if the top level ancestor content document of aDocument hasn't
+   * yet had the first contentful paint and there is a high priority event
+   * pending in the main thread.
+   */
+  static bool HighPriorityEventPendingForTopLevelDocumentBeforeContentfulPaint(
+      Document* aDocument);
+
+  /**
+   * Get the inner window corresponding to the incumbent global, including
+   * mapping extension content script globals to the attached window.
+   *
+   * Returns null if the incumbent global doesn't correspond to an inner window.
+   */
+  static nsGlobalWindowInner* IncumbentInnerWindow();
+
+  /**
+   * Get the inner window corresponding to the entry global, including mapping
+   * extension content script globals to the attached window.
+   *
+   * Returns null if the entry global doesn't correspond to an inner window.
+   */
+  static nsGlobalWindowInner* EntryInnerWindow();
+
+  /*
+   * Return safe area insets of window that defines as
+   * https://drafts.csswg.org/css-env-1/#safe-area-insets.
+   */
+  static mozilla::ScreenIntMargin GetWindowSafeAreaInsets(
+      nsIScreen* aScreen, const mozilla::ScreenIntMargin& aSafeareaInsets,
+      const mozilla::LayoutDeviceIntRect& aWindowRect);
+
+  struct SubresourceCacheValidationInfo {
+    // The expiration time, in seconds, if known.
+    mozilla::Maybe<uint32_t> mExpirationTime;
+    bool mMustRevalidate = false;
+  };
+
+  /**
+   * Gets cache validation info for subresources such as images or CSS
+   * stylesheets.
+   */
+  static SubresourceCacheValidationInfo GetSubresourceCacheValidationInfo(
+      nsIRequest*, nsIURI*);
+
+  static uint32_t SecondsFromPRTime(PRTime aTime) {
+    return uint32_t(int64_t(aTime) / int64_t(PR_USEC_PER_SEC));
+  }
+
+  /**
+   * Converts the given URL to a string and truncates it to the given length.
+   *
+   * Returns an empty string if aURL is null.
+   */
+  static nsCString TruncatedURLForDisplay(nsIURI* aURL, size_t aMaxLen = 128);
+
+  /**
+   * Anonymize the given id by hashing it with the provided origin. The
+   * resulting id will have the same length as the one that was passed in.
+   */
+  enum class OriginFormat {
+    Base64,
+    Plain,
+  };
+
+  static nsresult AnonymizeId(nsAString& aId, const nsACString& aOriginKey,
+                              OriginFormat aFormat = OriginFormat::Base64);
+
+  /**
+   * Return true if we should hide the synthetic browsing context for <object>
+   * or <embed> images in synthetic documents.
+   */
+  static bool ShouldHideObjectOrEmbedImageDocument();
+
+  /**
+   * Returns the object type that the object loading content will actually use
+   * to load the resource. Used for ORB and loading images into synthetic
+   * documents.
+   */
+  static uint32_t ResolveObjectType(uint32_t aType);
+
+  /**
+   * Create and load the string bundle for the 'aFile'.
+   * This API is used to preload the string bundle on the main thread so later
+   * other thread could access it.
+   */
+  static nsresult EnsureAndLoadStringBundle(PropertiesFile aFile);
+
+  /**
+   * The method asks nsIAppShell to prioritize Gecko's internal tasks over
+   * the OS level tasks for a short period of time.
+   */
+  static void RequestGeckoTaskBurst();
+
+  static void SetMayHaveFormCheckboxStateChangeListeners() {
+    sMayHaveFormCheckboxStateChangeListeners = true;
+  }
+
+  static bool MayHaveFormCheckboxStateChangeListeners() {
+    return sMayHaveFormCheckboxStateChangeListeners;
+  }
+
+  static void SetMayHaveFormRadioStateChangeListeners() {
+    sMayHaveFormRadioStateChangeListeners = true;
+  }
+
+  static bool MayHaveFormRadioStateChangeListeners() {
+    return sMayHaveFormRadioStateChangeListeners;
+  }
+
+  /**
+   * Returns the closest link element in the flat tree of aContent if there's
+   * one, otherwise returns nullptr.
+   */
+  static nsIContent* GetClosestLinkInFlatTree(nsIContent* aContent);
+
+  static bool IsExternalProtocol(nsIURI* aURI);
+
+ private:
+  static bool InitializeEventTable();
+
+  static nsresult EnsureStringBundle(PropertiesFile aFile);
+
+  static bool CanCallerAccess(nsIPrincipal* aSubjectPrincipal,
+                              nsIPrincipal* aPrincipal);
+
+  static nsresult WrapNative(JSContext* cx, nsISupports* native,
+                             nsWrapperCache* cache, const nsIID* aIID,
+                             JS::MutableHandle<JS::Value> vp,
+                             bool aAllowWrapping);
+
+  // TODO: Convert this to MOZ_CAN_RUN_SCRIPT (bug 1415230)
+  MOZ_CAN_RUN_SCRIPT_BOUNDARY static nsresult DispatchEvent(
+      Document* aDoc, nsISupports* aTarget, const nsAString& aEventName,
+      CanBubble, Cancelable, Composed, Trusted, bool* aDefaultAction = nullptr,
+      ChromeOnlyDispatch = ChromeOnlyDispatch::eNo);
+
+  // TODO: Convert this to MOZ_CAN_RUN_SCRIPT (bug 1415230)
+  MOZ_CAN_RUN_SCRIPT_BOUNDARY static nsresult DispatchEvent(
+      Document* aDoc, nsISupports* aTarget, mozilla::WidgetEvent& aWidgetEvent,
+      EventMessage aEventMessage, CanBubble, Cancelable, Trusted,
+      bool* aDefaultAction = nullptr,
+      ChromeOnlyDispatch = ChromeOnlyDispatch::eNo);
+
+  static void InitializeModifierStrings();
+
+  static void DropFragmentParsers();
+
+  static bool MatchClassNames(mozilla::dom::Element* aElement,
+                              int32_t aNamespaceID, nsAtom* aAtom, void* aData);
+  static void DestroyClassNameArray(void* aData);
+  static void* AllocClassMatchingInfo(nsINode* aRootNode,
+                                      const nsString* aClasses);
+
+  static mozilla::EventClassID GetEventClassIDFromMessage(
+      EventMessage aEventMessage);
+
+  // Fills in aInfo with the tokens from the supplied autocomplete attribute.
+  static AutocompleteAttrState InternalSerializeAutocompleteAttribute(
+      const nsAttrValue* aAttrVal, mozilla::dom::AutocompleteInfo& aInfo,
+      bool aGrantAllValidValue = false);
+
+  static mozilla::CallState CallOnAllRemoteChildren(
+      mozilla::dom::MessageBroadcaster* aManager,
+      const std::function<mozilla::CallState(mozilla::dom::BrowserParent*)>&
+          aCallback);
+
+  static nsINode* GetCommonAncestorHelper(nsINode* aNode1, nsINode* aNode2);
+  static nsIContent* GetCommonFlattenedTreeAncestorHelper(
+      nsIContent* aContent1, nsIContent* aContent2);
+
+  static nsIXPConnect* sXPConnect;
+
+  static nsIScriptSecurityManager* sSecurityManager;
+  static nsIPrincipal* sSystemPrincipal;
+  static nsIPrincipal* sNullSubjectPrincipal;
+
+  static nsIConsoleService* sConsoleService;
+
+  static nsTHashMap<nsRefPtrHashKey<nsAtom>, EventNameMapping>* sAtomEventTable;
+  static nsTHashMap<nsStringHashKey, EventNameMapping>* sStringEventTable;
+  static nsTArray<RefPtr<nsAtom>>* sUserDefinedEvents;
+
+  static nsIStringBundleService* sStringBundleService;
+  class nsContentUtilsReporter;
+
+  static nsIContentPolicy* sContentPolicyService;
+  static bool sTriedToGetContentPolicy;
+
+  static mozilla::StaticRefPtr<nsIBidiKeyboard> sBidiKeyboard;
+
+  static bool sInitialized;
+  static uint32_t sScriptBlockerCount;
+  static uint32_t sDOMNodeRemovedSuppressCount;
+
+  // Not an nsCOMArray because removing elements from those is slower
+  static AutoTArray<nsCOMPtr<nsIRunnable>, 8>* sBlockedScriptRunners;
+  static uint32_t sRunnersCountAtFirstBlocker;
+  static uint32_t sScriptBlockerCountWhereRunnersPrevented;
+
+  static nsIInterfaceRequestor* sSameOriginChecker;
+
+  static bool sIsHandlingKeyBoardEvent;
+#ifndef RELEASE_OR_BETA
+  static bool sBypassCSSOMOriginCheck;
+#endif
+
+  class UserInteractionObserver;
+  static UserInteractionObserver* sUserInteractionObserver;
+
+  static nsHtml5StringParser* sHTMLFragmentParser;
+  static nsParser* sXMLFragmentParser;
+  static nsIFragmentContentSink* sXMLFragmentSink;
+
+  /**
+   * True if there's a fragment parser activation on the stack.
+   */
+  static bool sFragmentParsingActive;
+
+  static nsString* sShiftText;
+  static nsString* sControlText;
+  static nsString* sMetaText;
+  static nsString* sOSText;
+  static nsString* sAltText;
+  static nsString* sModifierSeparator;
+
+  // Alternate data mime types, used by the ScriptLoader to register and read
+  // the bytecode out of the nsCacheInfoChannel.
+  static nsCString* sJSScriptBytecodeMimeType;
+  static nsCString* sJSModuleBytecodeMimeType;
+
+  static mozilla::LazyLogModule gResistFingerprintingLog;
+  static mozilla::LazyLogModule sDOMDumpLog;
+
+  static int32_t sInnerOrOuterWindowCount;
+  static uint32_t sInnerOrOuterWindowSerialCounter;
+
+  static bool sMayHaveFormCheckboxStateChangeListeners;
+  static bool sMayHaveFormRadioStateChangeListeners;
+};
+
+/* static */ inline ExtContentPolicyType
+nsContentUtils::InternalContentPolicyTypeToExternal(nsContentPolicyType aType) {
+  switch (aType) {
+    case nsIContentPolicy::TYPE_INTERNAL_SCRIPT:
+    case nsIContentPolicy::TYPE_INTERNAL_SCRIPT_PRELOAD:
+    case nsIContentPolicy::TYPE_INTERNAL_MODULE:
+    case nsIContentPolicy::TYPE_INTERNAL_MODULE_PRELOAD:
+    case nsIContentPolicy::TYPE_INTERNAL_WORKER:
+    case nsIContentPolicy::TYPE_INTERNAL_SHARED_WORKER:
+    case nsIContentPolicy::TYPE_INTERNAL_SERVICE_WORKER:
+    case nsIContentPolicy::TYPE_INTERNAL_WORKER_IMPORT_SCRIPTS:
+    case nsIContentPolicy::TYPE_INTERNAL_WORKER_STATIC_MODULE:
+    case nsIContentPolicy::TYPE_INTERNAL_AUDIOWORKLET:
+    case nsIContentPolicy::TYPE_INTERNAL_PAINTWORKLET:
+    case nsIContentPolicy::TYPE_INTERNAL_CHROMEUTILS_COMPILED_SCRIPT:
+    case nsIContentPolicy::TYPE_INTERNAL_FRAME_MESSAGEMANAGER_SCRIPT:
+      return ExtContentPolicy::TYPE_SCRIPT;
+
+    case nsIContentPolicy::TYPE_INTERNAL_EMBED:
+    case nsIContentPolicy::TYPE_INTERNAL_OBJECT:
+      return ExtContentPolicy::TYPE_OBJECT;
+
+    case nsIContentPolicy::TYPE_INTERNAL_FRAME:
+    case nsIContentPolicy::TYPE_INTERNAL_IFRAME:
+      return ExtContentPolicy::TYPE_SUBDOCUMENT;
+
+    case nsIContentPolicy::TYPE_INTERNAL_AUDIO:
+    case nsIContentPolicy::TYPE_INTERNAL_VIDEO:
+    case nsIContentPolicy::TYPE_INTERNAL_TRACK:
+      return ExtContentPolicy::TYPE_MEDIA;
+
+    case nsIContentPolicy::TYPE_INTERNAL_XMLHTTPREQUEST:
+    case nsIContentPolicy::TYPE_INTERNAL_EVENTSOURCE:
+      return ExtContentPolicy::TYPE_XMLHTTPREQUEST;
+
+    case nsIContentPolicy::TYPE_INTERNAL_IMAGE:
+    case nsIContentPolicy::TYPE_INTERNAL_IMAGE_PRELOAD:
+    case nsIContentPolicy::TYPE_INTERNAL_IMAGE_FAVICON:
+      return ExtContentPolicy::TYPE_IMAGE;
+
+    case nsIContentPolicy::TYPE_INTERNAL_STYLESHEET:
+    case nsIContentPolicy::TYPE_INTERNAL_STYLESHEET_PRELOAD:
+      return ExtContentPolicy::TYPE_STYLESHEET;
+
+    case nsIContentPolicy::TYPE_INTERNAL_DTD:
+    case nsIContentPolicy::TYPE_INTERNAL_FORCE_ALLOWED_DTD:
+      return ExtContentPolicy::TYPE_DTD;
+
+    case nsIContentPolicy::TYPE_INTERNAL_FONT_PRELOAD:
+      return ExtContentPolicy::TYPE_FONT;
+
+    case nsIContentPolicy::TYPE_INTERNAL_FETCH_PRELOAD:
+      return ExtContentPolicy::TYPE_FETCH;
+
+    default:
+      return static_cast<ExtContentPolicyType>(aType);
+  }
+}
+
+namespace mozilla {
+std::ostream& operator<<(
+    std::ostream& aOut,
+    const mozilla::PreventDefaultResult aPreventDefaultResult);
+}  // namespace mozilla
+
+class MOZ_RAII nsAutoScriptBlocker {
+ public:
+  explicit nsAutoScriptBlocker() { nsContentUtils::AddScriptBlocker(); }
+  ~nsAutoScriptBlocker() { nsContentUtils::RemoveScriptBlocker(); }
+
+ private:
+};
+
+class MOZ_STACK_CLASS nsAutoScriptBlockerSuppressNodeRemoved
+    : public nsAutoScriptBlocker {
+ public:
+  nsAutoScriptBlockerSuppressNodeRemoved() {
+    ++nsContentUtils::sDOMNodeRemovedSuppressCount;
+  }
+  ~nsAutoScriptBlockerSuppressNodeRemoved() {
+    --nsContentUtils::sDOMNodeRemovedSuppressCount;
+  }
+};
+
+namespace mozilla::dom {
+
+class TreeOrderComparator {
+ public:
+  bool Equals(nsINode* aElem1, nsINode* aElem2) const {
+    return aElem1 == aElem2;
+  }
+  bool LessThan(nsINode* aElem1, nsINode* aElem2) const {
+    return nsContentUtils::PositionIsBefore(aElem1, aElem2);
+  }
+};
+
+}  // namespace mozilla::dom
+
+#define NS_INTERFACE_MAP_ENTRY_TEAROFF(_interface, _allocator) \
+  NS_INTERFACE_MAP_ENTRY_TEAROFF_AMBIGUOUS(_interface, _interface, _allocator)
+
+#define NS_INTERFACE_MAP_ENTRY_TEAROFF_AMBIGUOUS(_interface, _implClass, \
+                                                 _allocator)             \
+  if (aIID.Equals(NS_GET_IID(_interface))) {                             \
+    foundInterface = static_cast<_implClass*>(_allocator);               \
+    if (!foundInterface) {                                               \
+      *aInstancePtr = nullptr;                                           \
+      return NS_ERROR_OUT_OF_MEMORY;                                     \
+    }                                                                    \
+  } else
+
+/*
+ * In the following helper macros we exploit the fact that the result of a
+ * series of additions will not be finite if any one of the operands in the
+ * series is not finite.
+ */
+#define NS_ENSURE_FINITE(f, rv) \
+  if (!std::isfinite(f)) {      \
+    return (rv);                \
+  }
+
+#define NS_ENSURE_FINITE2(f1, f2, rv) \
+  if (!std::isfinite((f1) + (f2))) {  \
+    return (rv);                      \
+  }
+
+#define NS_ENSURE_FINITE4(f1, f2, f3, f4, rv)      \
+  if (!std::isfinite((f1) + (f2) + (f3) + (f4))) { \
+    return (rv);                                   \
+  }
+
+#define NS_ENSURE_FINITE5(f1, f2, f3, f4, f5, rv)         \
+  if (!std::isfinite((f1) + (f2) + (f3) + (f4) + (f5))) { \
+    return (rv);                                          \
+  }
+
+#define NS_ENSURE_FINITE6(f1, f2, f3, f4, f5, f6, rv)            \
+  if (!std::isfinite((f1) + (f2) + (f3) + (f4) + (f5) + (f6))) { \
+    return (rv);                                                 \
+  }
+
+// Deletes a linked list iteratively to avoid blowing up the stack (bug 460444).
+#define NS_CONTENT_DELETE_LIST_MEMBER(type_, ptr_, member_) \
+  {                                                         \
+    type_* cur = (ptr_)->member_;                           \
+    (ptr_)->member_ = nullptr;                              \
+    while (cur) {                                           \
+      type_* next = cur->member_;                           \
+      cur->member_ = nullptr;                               \
+      delete cur;                                           \
+      cur = next;                                           \
+    }                                                       \
+  }
+
+#endif /* nsContentUtils_h___ */