Adding upstream version 124.0.1.upstream/124.0.1

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

1 files changed, 615 insertions, 0 deletions

diff --git a/layout/style/StyleSheet.h b/layout/style/StyleSheet.h
new file mode 100644
index 0000000000..1dbcad1e01
--- /dev/null
+++ b/layout/style/StyleSheet.h
@@ -0,0 +1,615 @@
+/* -*- 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/. */
+
+#ifndef mozilla_StyleSheet_h
+#define mozilla_StyleSheet_h
+
+#include "mozilla/css/SheetParsingMode.h"
+#include "mozilla/dom/CSSStyleSheetBinding.h"
+#include "mozilla/dom/SRIMetadata.h"
+#include "mozilla/CORSMode.h"
+#include "mozilla/MozPromise.h"
+#include "mozilla/RefPtr.h"
+#include "mozilla/ServoBindingTypes.h"
+#include "mozilla/ServoTypes.h"
+#include "mozilla/StyleSheetInfo.h"
+#include "nsICSSLoaderObserver.h"
+#include "nsIPrincipal.h"
+#include "nsWrapperCache.h"
+#include "nsStringFwd.h"
+
+class nsIGlobalObject;
+class nsINode;
+class nsIPrincipal;
+struct StyleLockedCssRules;
+class nsIReferrerInfo;
+
+namespace mozilla {
+
+class ServoCSSRuleList;
+class ServoStyleSet;
+
+using StyleSheetParsePromise = MozPromise</* Dummy */ bool,
+                                          /* Dummy */ bool,
+                                          /* IsExclusive = */ true>;
+
+enum class StyleRuleChangeKind : uint32_t;
+
+namespace css {
+class GroupRule;
+class Loader;
+class LoaderReusableStyleSheets;
+class Rule;
+class SheetLoadData;
+}  // namespace css
+
+namespace dom {
+class CSSImportRule;
+class CSSRuleList;
+class DocumentOrShadowRoot;
+class MediaList;
+class ShadowRoot;
+struct CSSStyleSheetInit;
+}  // namespace dom
+
+enum class StyleSheetState : uint8_t {
+  // Whether the sheet is disabled. Sheets can be made disabled via CSSOM, or
+  // via alternate links and such.
+  Disabled = 1 << 0,
+  // Whether the sheet is complete. The sheet is complete if it's finished
+  // loading. See StyleSheet::SetComplete.
+  Complete = 1 << 1,
+  // Whether we've forced a unique inner. StyleSheet objects share an 'inner'
+  // StyleSheetInfo object if they share URL, CORS mode, etc.
+  //
+  // See the Loader's `mCompleteSheets` and `mLoadingSheets`.
+  ForcedUniqueInner = 1 << 2,
+  // Whether this stylesheet has suffered any modification to the rules via
+  // CSSOM.
+  ModifiedRules = 1 << 3,
+  // Same flag, but devtools clears it in some specific situations.
+  //
+  // Used to control whether devtools shows the rule in its authored form or
+  // not.
+  ModifiedRulesForDevtools = 1 << 4,
+  // Whether modifications to the sheet are currently disallowed.
+  // This flag is set during the async Replace() function to ensure
+  // that the sheet is not modified until the promise is resolved.
+  ModificationDisallowed = 1 << 5,
+};
+
+MOZ_MAKE_ENUM_CLASS_BITWISE_OPERATORS(StyleSheetState)
+
+class StyleSheet final : public nsICSSLoaderObserver, public nsWrapperCache {
+  StyleSheet(const StyleSheet& aCopy, StyleSheet* aParentSheetToUse,
+             dom::DocumentOrShadowRoot* aDocOrShadowRootToUse,
+             dom::Document* aConstructorDocToUse);
+
+  virtual ~StyleSheet();
+
+  using State = StyleSheetState;
+
+ public:
+  StyleSheet(css::SheetParsingMode aParsingMode, CORSMode aCORSMode,
+             const dom::SRIMetadata& aIntegrity);
+
+  static already_AddRefed<StyleSheet> Constructor(const dom::GlobalObject&,
+                                                  const dom::CSSStyleSheetInit&,
+                                                  ErrorResult&);
+
+  NS_DECL_CYCLE_COLLECTING_ISUPPORTS
+  NS_DECL_CYCLE_COLLECTION_WRAPPERCACHE_CLASS(StyleSheet)
+
+  already_AddRefed<StyleSheet> CreateEmptyChildSheet(
+      already_AddRefed<dom::MediaList> aMediaList) const;
+
+  bool HasRules() const;
+
+  // Parses a stylesheet. The load data argument corresponds to the
+  // SheetLoadData for this stylesheet.
+  // NOTE: ParseSheet can run synchronously or asynchronously
+  //       based on the result of `AllowParallelParse`
+  RefPtr<StyleSheetParsePromise> ParseSheet(css::Loader&,
+                                            const nsACString& aBytes,
+                                            css::SheetLoadData&);
+
+  // Common code that needs to be called after servo finishes parsing. This is
+  // shared between the parallel and sequential paths.
+  void FinishAsyncParse(already_AddRefed<StyleStylesheetContents>,
+                        UniquePtr<StyleUseCounters>);
+
+  // Similar to `ParseSheet`, but guarantees that
+  // parsing will be performed synchronously.
+  // NOTE: ParseSheet can still run synchronously.
+  //       This is not a strict alternative.
+  //
+  // The load data may be null sometimes.
+  void ParseSheetSync(
+      css::Loader* aLoader, const nsACString& aBytes,
+      css::SheetLoadData* aLoadData,
+      css::LoaderReusableStyleSheets* aReusableSheets = nullptr);
+
+  void ReparseSheet(const nsACString& aInput, ErrorResult& aRv);
+
+  const StyleStylesheetContents* RawContents() const {
+    return Inner().mContents;
+  }
+
+  const StyleUseCounters* GetStyleUseCounters() const {
+    return Inner().mUseCounters.get();
+  }
+
+  URLExtraData* URLData() const { return Inner().mURLData; }
+
+  // nsICSSLoaderObserver interface
+  NS_IMETHOD StyleSheetLoaded(StyleSheet* aSheet, bool aWasDeferred,
+                              nsresult aStatus) final;
+
+  // Internal GetCssRules methods which do not have security check and
+  // completeness check.
+  ServoCSSRuleList* GetCssRulesInternal();
+
+  // Returns the stylesheet's Servo origin as a StyleOrigin value.
+  StyleOrigin GetOrigin() const;
+
+  void SetOwningNode(nsINode* aOwningNode) { mOwningNode = aOwningNode; }
+
+  css::SheetParsingMode ParsingMode() const { return mParsingMode; }
+  dom::CSSStyleSheetParsingMode ParsingModeDOM();
+
+  /**
+   * Whether the sheet is complete.
+   */
+  bool IsComplete() const { return bool(mState & State::Complete); }
+
+  void SetComplete();
+
+  void SetEnabled(bool aEnabled) { SetDisabled(!aEnabled); }
+
+  // Whether the sheet is for an inline <style> element.
+  bool IsInline() const { return !GetOriginalURI(); }
+
+  nsIURI* GetSheetURI() const { return Inner().mSheetURI; }
+
+  /**
+   * Get the URI this sheet was originally loaded from, if any. Can return null.
+   */
+  nsIURI* GetOriginalURI() const { return Inner().mOriginalSheetURI; }
+
+  nsIURI* GetBaseURI() const { return Inner().mBaseURI; }
+
+  /**
+   * SetURIs must be called on all sheets before parsing into them.
+   * SetURIs may only be called while the sheet is 1) incomplete and 2)
+   * has no rules in it.
+   *
+   * FIXME(emilio): Can we pass this down when constructing the sheet instead?
+   */
+  inline void SetURIs(nsIURI* aSheetURI, nsIURI* aOriginalSheetURI,
+                      nsIURI* aBaseURI);
+
+  /**
+   * Whether the sheet is applicable.  A sheet that is not applicable
+   * should never be inserted into a style set.  A sheet may not be
+   * applicable for a variety of reasons including being disabled and
+   * being incomplete.
+   */
+  bool IsApplicable() const { return !Disabled() && IsComplete(); }
+
+  already_AddRefed<StyleSheet> Clone(
+      StyleSheet* aCloneParent,
+      dom::DocumentOrShadowRoot* aCloneDocumentOrShadowRoot) const;
+
+  /**
+   * Creates a clone of the adopted style sheet as though it were constructed
+   * by aConstructorDocument. This should only be used for printing.
+   */
+  already_AddRefed<StyleSheet> CloneAdoptedSheet(
+      dom::Document& aConstructorDocument) const;
+
+  bool HasForcedUniqueInner() const {
+    return bool(mState & State::ForcedUniqueInner);
+  }
+
+  bool HasModifiedRules() const { return bool(mState & State::ModifiedRules); }
+
+  bool HasModifiedRulesForDevtools() const {
+    return bool(mState & State::ModifiedRulesForDevtools);
+  }
+
+  bool HasUniqueInner() const { return Inner().mSheets.Length() == 1; }
+
+  void AssertHasUniqueInner() const { MOZ_ASSERT(HasUniqueInner()); }
+
+  void EnsureUniqueInner();
+
+  // Returns the DocumentOrShadowRoot* that owns us, if any.
+  //
+  // TODO(emilio): Maybe rename to GetOwner*() or such? Might be
+  // confusing with nsINode::OwnerDoc and such.
+  dom::DocumentOrShadowRoot* GetAssociatedDocumentOrShadowRoot() const;
+
+  // Whether this stylesheet is kept alive by the associated or constructor
+  // document somehow, and thus at least has the same lifetime as
+  // GetAssociatedDocument().
+  dom::Document* GetKeptAliveByDocument() const;
+
+  // If this is a constructed style sheet, return mConstructorDocument.
+  // Otherwise return the document we're associated to,
+  // via mDocumentOrShadowRoot.
+  //
+  // Non-null iff GetAssociatedDocumentOrShadowRoot is non-null.
+  dom::Document* GetAssociatedDocument() const;
+
+  void SetAssociatedDocumentOrShadowRoot(dom::DocumentOrShadowRoot*);
+  void ClearAssociatedDocumentOrShadowRoot() {
+    SetAssociatedDocumentOrShadowRoot(nullptr);
+  }
+
+  nsINode* GetOwnerNode() const { return mOwningNode; }
+
+  nsINode* GetOwnerNodeOfOutermostSheet() const {
+    return OutermostSheet().GetOwnerNode();
+  }
+
+  StyleSheet* GetParentSheet() const { return mParentSheet; }
+
+  void AddReferencingRule(dom::CSSImportRule& aRule) {
+    MOZ_ASSERT(!mReferencingRules.Contains(&aRule));
+    mReferencingRules.AppendElement(&aRule);
+  }
+
+  void RemoveReferencingRule(dom::CSSImportRule& aRule) {
+    MOZ_ASSERT(mReferencingRules.Contains(&aRule));
+    mReferencingRules.RemoveElement(&aRule);
+  }
+
+  // Note that when exposed to script, this should always have a <= 1 length.
+  // CSSImportRule::GetStyleSheetForBindings takes care of that.
+  dom::CSSImportRule* GetOwnerRule() const {
+    return mReferencingRules.SafeElementAt(0);
+  }
+
+  void AppendStyleSheet(StyleSheet&);
+
+  // Append a stylesheet to the child list without calling WillDirty.
+  void AppendStyleSheetSilently(StyleSheet&);
+
+  const nsTArray<RefPtr<StyleSheet>>& ChildSheets() const {
+#ifdef DEBUG
+    for (StyleSheet* child : Inner().mChildren) {
+      MOZ_ASSERT(child->GetParentSheet());
+      MOZ_ASSERT(child->GetParentSheet()->mInner == mInner);
+    }
+#endif
+    return Inner().mChildren;
+  }
+
+  // Principal() never returns a null pointer.
+  nsIPrincipal* Principal() const { return Inner().mPrincipal; }
+
+  /**
+   * SetPrincipal should be called on all sheets before parsing into them.
+   * This can only be called once with a non-null principal.
+   *
+   * Calling this with a null pointer is allowed and is treated as a no-op.
+   *
+   * FIXME(emilio): Can we get this at construction time instead?
+   */
+  void SetPrincipal(nsIPrincipal* aPrincipal) {
+    StyleSheetInfo& info = Inner();
+    MOZ_ASSERT(!info.mPrincipalSet, "Should only set principal once");
+    if (aPrincipal) {
+      info.mPrincipal = aPrincipal;
+#ifdef DEBUG
+      info.mPrincipalSet = true;
+#endif
+    }
+  }
+
+  void SetTitle(const nsAString& aTitle) { mTitle = aTitle; }
+  void SetMedia(already_AddRefed<dom::MediaList> aMedia);
+
+  // Get this style sheet's CORS mode
+  CORSMode GetCORSMode() const { return Inner().mCORSMode; }
+
+  // Get this style sheet's ReferrerInfo
+  nsIReferrerInfo* GetReferrerInfo() const { return Inner().mReferrerInfo; }
+
+  // Set this style sheet's ReferrerInfo
+  void SetReferrerInfo(nsIReferrerInfo* aReferrerInfo) {
+    Inner().mReferrerInfo = aReferrerInfo;
+  }
+
+  // Get this style sheet's integrity metadata
+  void GetIntegrity(dom::SRIMetadata& aResult) const {
+    aResult = Inner().mIntegrity;
+  }
+
+  size_t SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) const;
+#if defined(DEBUG) || defined(MOZ_LAYOUT_DEBUGGER)
+  void List(FILE* aOut = stdout, int32_t aIndex = 0);
+#endif
+
+  // WebIDL StyleSheet API
+  void GetType(nsAString& aType);
+  void GetHref(nsAString& aHref, ErrorResult& aRv);
+  // GetOwnerNode is defined above.
+  StyleSheet* GetParentStyleSheet() const { return GetParentSheet(); }
+  void GetTitle(nsAString& aTitle);
+  dom::MediaList* Media();
+  bool Disabled() const { return bool(mState & State::Disabled); }
+  void SetDisabled(bool aDisabled);
+
+  void GetSourceMapURL(nsACString&);
+  void SetSourceMapURL(nsCString&&);
+  void GetSourceURL(nsACString& aSourceURL);
+
+  // WebIDL CSSStyleSheet API
+  // Can't be inline because we can't include ImportRule here.  And can't be
+  // called GetOwnerRule because that would be ambiguous with the ImportRule
+  // version.
+  css::Rule* GetDOMOwnerRule() const;
+  dom::CSSRuleList* GetCssRules(nsIPrincipal& aSubjectPrincipal, ErrorResult&);
+  uint32_t InsertRule(const nsACString& aRule, uint32_t aIndex,
+                      nsIPrincipal& aSubjectPrincipal, ErrorResult& aRv);
+  void DeleteRule(uint32_t aIndex, nsIPrincipal& aSubjectPrincipal,
+                  ErrorResult& aRv);
+  int32_t AddRule(const nsACString& aSelector, const nsACString& aBlock,
+                  const dom::Optional<uint32_t>& aIndex,
+                  nsIPrincipal& aSubjectPrincipal, ErrorResult& aRv);
+  already_AddRefed<dom::Promise> Replace(const nsACString& aText, ErrorResult&);
+  void ReplaceSync(const nsACString& aText, ErrorResult&);
+  bool ModificationDisallowed() const {
+    return bool(mState & State::ModificationDisallowed);
+  }
+
+  // Called before and after the asynchronous Replace() function
+  // to disable/re-enable modification while there is a pending promise.
+  void SetModificationDisallowed(bool aDisallowed) {
+    MOZ_ASSERT(IsConstructed());
+    MOZ_ASSERT(!IsReadOnly());
+    if (aDisallowed) {
+      mState |= State::ModificationDisallowed;
+      // Sheet will be re-set to complete when its rules are replaced
+      mState &= ~State::Complete;
+      if (!Disabled()) {
+        ApplicableStateChanged(false);
+      }
+    } else {
+      mState &= ~State::ModificationDisallowed;
+    }
+  }
+
+  // True if the sheet was created through the Constructable StyleSheets API
+  bool IsConstructed() const { return !!mConstructorDocument; }
+
+  // True if any of this sheet's ancestors were created through the
+  // Constructable StyleSheets API
+  bool SelfOrAncestorIsConstructed() const {
+    return OutermostSheet().IsConstructed();
+  }
+
+  // Ture if the sheet's constructor document matches the given document
+  bool ConstructorDocumentMatches(const dom::Document& aDocument) const {
+    return mConstructorDocument == &aDocument;
+  }
+
+  // Add a document or shadow root to the list of adopters.
+  // Adopters will be notified when styles are changed.
+  void AddAdopter(dom::DocumentOrShadowRoot& aAdopter) {
+    MOZ_ASSERT(IsConstructed());
+    MOZ_ASSERT(!mAdopters.Contains(&aAdopter));
+    mAdopters.AppendElement(&aAdopter);
+  }
+
+  // Remove a document or shadow root from the list of adopters.
+  void RemoveAdopter(dom::DocumentOrShadowRoot& aAdopter) {
+    // Cannot assert IsConstructed() because this can run after unlink.
+    mAdopters.RemoveElement(&aAdopter);
+  }
+
+  const nsTArray<dom::DocumentOrShadowRoot*>& SelfOrAncestorAdopters() const {
+    return OutermostSheet().mAdopters;
+  }
+
+  // WebIDL miscellaneous bits
+  inline dom::ParentObject GetParentObject() const;
+  JSObject* WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) final;
+
+  // Changes to sheets should be after a WillDirty call.
+  void WillDirty();
+
+  // Called when a rule changes from CSSOM.
+  //
+  // FIXME(emilio): This shouldn't allow null, but MediaList doesn't know about
+  // its owning media rule, plus it's used for the stylesheet media itself.
+  void RuleChanged(css::Rule*, StyleRuleChangeKind);
+
+  void AddStyleSet(ServoStyleSet* aStyleSet);
+  void DropStyleSet(ServoStyleSet* aStyleSet);
+
+  nsresult DeleteRuleFromGroup(css::GroupRule* aGroup, uint32_t aIndex);
+  nsresult InsertRuleIntoGroup(const nsACString& aRule, css::GroupRule* aGroup,
+                               uint32_t aIndex);
+
+  // Find the ID of the owner inner window.
+  uint64_t FindOwningWindowInnerID() const;
+
+  // Copy the contents of this style sheet into the shared memory buffer managed
+  // by aBuilder.  Returns the pointer into the buffer that the sheet contents
+  // were stored at.  (The returned pointer is to an Arc<Locked<Rules>> value,
+  // or null, with a filled in aErrorMessage, on failure.)
+  const StyleLockedCssRules* ToShared(StyleSharedMemoryBuilder* aBuilder,
+                                      nsCString& aErrorMessage);
+
+  // Sets the contents of this style sheet to the specified aSharedRules
+  // pointer, which must be a pointer somewhere in the aSharedMemory buffer
+  // as previously returned by a ToShared() call.
+  void SetSharedContents(const StyleLockedCssRules* aSharedRules);
+
+  // Whether this style sheet should not allow any modifications.
+  //
+  // This is true for any User Agent sheets once they are complete.
+  bool IsReadOnly() const;
+
+  // Removes a stylesheet from its parent sheet child list, if any.
+  void RemoveFromParent();
+
+  // Resolves mReplacePromise with this sheet.
+  void MaybeResolveReplacePromise();
+
+  // Rejects mReplacePromise with a NetworkError.
+  void MaybeRejectReplacePromise();
+
+  // Gets the relevant global if exists.
+  nsISupports* GetRelevantGlobal() const;
+
+ private:
+  void SetModifiedRules() {
+    mState |= State::ModifiedRules | State::ModifiedRulesForDevtools;
+  }
+
+  const StyleSheet& OutermostSheet() const {
+    const auto* current = this;
+    while (current->mParentSheet) {
+      MOZ_ASSERT(!current->mDocumentOrShadowRoot,
+                 "Shouldn't be set on child sheets");
+      MOZ_ASSERT(!current->mConstructorDocument,
+                 "Shouldn't be set on child sheets");
+      current = current->mParentSheet;
+    }
+    return *current;
+  }
+
+  StyleSheetInfo& Inner() {
+    MOZ_ASSERT(mInner);
+    return *mInner;
+  }
+
+  const StyleSheetInfo& Inner() const {
+    MOZ_ASSERT(mInner);
+    return *mInner;
+  }
+
+  // Check if the rules are available for read and write.
+  // It does the security check as well as whether the rules have been
+  // completely loaded. aRv will have an exception set if this function
+  // returns false.
+  bool AreRulesAvailable(nsIPrincipal& aSubjectPrincipal, ErrorResult& aRv);
+
+  void SetURLExtraData();
+
+ protected:
+  // Internal methods which do not have security check and completeness check.
+  uint32_t InsertRuleInternal(const nsACString& aRule, uint32_t aIndex,
+                              ErrorResult&);
+  void DeleteRuleInternal(uint32_t aIndex, ErrorResult&);
+  nsresult InsertRuleIntoGroupInternal(const nsACString& aRule,
+                                       css::GroupRule* aGroup, uint32_t aIndex);
+
+  // Take the recently cloned sheets from the `@import` rules, and reparent them
+  // correctly to `aPrimarySheet`.
+  void FixUpAfterInnerClone();
+
+  // aFromClone says whether this comes from a clone of the stylesheet (and thus
+  // we should also fix up the wrappers for the individual rules in the rule
+  // lists).
+  void FixUpRuleListAfterContentsChangeIfNeeded(bool aFromClone = false);
+
+  void DropRuleList();
+
+  // Called when a rule is removed from the sheet from CSSOM.
+  void RuleAdded(css::Rule&);
+
+  // Called when a rule is added to the sheet from CSSOM.
+  void RuleRemoved(css::Rule&);
+
+  // Called when a stylesheet is cloned.
+  void StyleSheetCloned(StyleSheet&);
+
+  // Notifies that the applicable state changed.
+  // aApplicable is the value that we expect to get from IsApplicable().
+  // assertion will fail if the expectation does not match reality.
+  void ApplicableStateChanged(bool aApplicable);
+
+  void LastRelease();
+
+  // Return success if the subject principal subsumes the principal of our
+  // inner, error otherwise.  This will also succeed if access is allowed by
+  // CORS.  In that case, it will set the principal of the inner to the
+  // subject principal.
+  void SubjectSubsumesInnerPrincipal(nsIPrincipal& aSubjectPrincipal,
+                                     ErrorResult& aRv);
+
+  // Drop our reference to mMedia
+  void DropMedia();
+  // Set our relevant global if needed.
+  void UpdateRelevantGlobal();
+  // Unlink our inner, if needed, for cycle collection.
+  void UnlinkInner();
+  // Traverse our inner, if needed, for cycle collection
+  void TraverseInner(nsCycleCollectionTraversalCallback&);
+
+  // Return whether the given @import rule has pending child sheet.
+  static bool RuleHasPendingChildSheet(css::Rule* aRule);
+
+  StyleSheet* mParentSheet;  // weak ref
+
+  // A pointer to the sheet's relevant global object. This is populated when the
+  // sheet gets an associated document and is complete.
+  //
+  // This is required for the sheet to be able to create a promise.
+  // https://html.spec.whatwg.org/#concept-relevant-everything
+  nsCOMPtr<nsIGlobalObject> mRelevantGlobal;
+
+  RefPtr<dom::Document> mConstructorDocument;
+
+  // Will be set in the Replace() function and resolved/rejected by the
+  // sheet once its rules have been replaced and the sheet is complete again.
+  RefPtr<dom::Promise> mReplacePromise;
+
+  nsString mTitle;
+
+  // weak ref; parents maintain this for their children
+  dom::DocumentOrShadowRoot* mDocumentOrShadowRoot;
+  nsINode* mOwningNode = nullptr;                   // weak ref
+  nsTArray<dom::CSSImportRule*> mReferencingRules;  // weak ref
+
+  RefPtr<dom::MediaList> mMedia;
+
+  // mParsingMode controls access to nonstandard style constructs that
+  // are not safe for use on the public Web but necessary in UA sheets
+  // and/or useful in user sheets.
+  //
+  // FIXME(emilio): Given we store the parsed contents in the Inner, this should
+  // probably also move there.
+  css::SheetParsingMode mParsingMode;
+
+  State mState;
+
+  // Core information we get from parsed sheets, which are shared amongst
+  // StyleSheet clones.
+  //
+  // Always nonnull until LastRelease().
+  StyleSheetInfo* mInner;
+
+  nsTArray<ServoStyleSet*> mStyleSets;
+
+  RefPtr<ServoCSSRuleList> mRuleList;
+
+  MozPromiseHolder<StyleSheetParsePromise> mParsePromise;
+
+  nsTArray<dom::DocumentOrShadowRoot*> mAdopters;
+
+  // Make StyleSheetInfo and subclasses into friends so they can use
+  // ChildSheetListBuilder.
+  friend struct StyleSheetInfo;
+};
+
+}  // namespace mozilla
+
+#endif  // mozilla_StyleSheet_h