CSS Font Loading: FontFaceSet.ready should return the same promise each time

Source/core/css/FontFaceSet.h

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 37 matching lines @@
 
 class CSSFontFace;
 class CSSFontFaceSource;
 class CSSFontSelector;
 class Dictionary;
 class Document;
 class ExceptionState;
 class Font;
 class FontFaceCache;
 class FontResource;
-class FontsReadyPromiseResolver;
 class ExecutionContext;
 
 #if ENABLE(OILPAN)
 class FontFaceSet final : public EventTargetWithInlineData, public HeapSupplement<Document>, public ActiveDOMObject {
     USING_GARBAGE_COLLECTED_MIXIN(FontFaceSet);
     typedef HeapSupplement<Document> SupplementType;
 #else
 class FontFaceSet final : public EventTargetWithInlineData, public RefCountedSupplement<Document, FontFaceSet>, public ActiveDOMObject {
     REFCOUNTED_EVENT_TARGET(FontFaceSet);
     typedef RefCountedSupplement<Document, FontFaceSet> SupplementType;
@@ skipping 69 matching lines @@
     void forEachInternal(FontFaceSetForEachCallback*, const ScriptValue* thisArg) const;
     void addToLoadingFonts(PassRefPtrWillBeRawPtr<FontFace>);
     void removeFromLoadingFonts(PassRefPtrWillBeRawPtr<FontFace>);
     void fireLoadingEvent();
     void fireDoneEventIfPossible();
     bool resolveFontStyle(const String&, Font&);
     void handlePendingEventsAndPromisesSoon();
     void handlePendingEventsAndPromises();
     const WillBeHeapListHashSet<RefPtrWillBeMember<FontFace>>& cssConnectedFontFaceList() const;
     bool isCSSConnectedFontFace(FontFace*) const;
+    bool shouldSignalReady() const;
+
+    typedef ScriptPromiseProperty<RawPtrWillBeMember<FontFaceSet>, RawPtrWillBeMember<FontFaceSet>, Member<DOMException>> ReadyProperty;
 
     WillBeHeapHashSet<RefPtrWillBeMember<FontFace>> m_loadingFonts;
     bool m_shouldFireLoadingEvent;
     bool m_isLoading;
-    PersistentHeapVectorWillBeHeapVector<Member<FontsReadyPromiseResolver>> m_readyResolvers;
+    PersistentWillBeMember<ReadyProperty> m_ready;
     FontFaceArray m_loadedFonts;
     FontFaceArray m_failedFonts;
     WillBeHeapListHashSet<RefPtrWillBeMember<FontFace>> m_nonCSSConnectedFaces;
 
     AsyncMethodRunner<FontFaceSet> m_asyncRunner;
 
     FontLoadHistogram m_histogram;
 };
 
 } // namespace blink
 
 #endif // FontFaceSet_h