[DO NOT COMMIT] Trace events for layout-based First Meaningful Paint detection

third_party/WebKit/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 71 matching lines @@
     ExecutionContext* getExecutionContext() const override;
     const AtomicString& interfaceName() const override;
 
     Document* document() const;
 
     void didLayout();
     void beginFontLoading(FontFace*);
     void fontLoaded(FontFace*);
     void loadError(FontFace*);
 
+    bool hasBlankText() const;
+
     // ActiveDOMObject
     void suspend() override;
     void resume() override;
     void stop() override;
 
     static FontFaceSet* from(Document&);
     static void didLayout(Document&);
+    static bool hasBlankText(Document&);
 
     void addFontFacesToFontFaceCache(FontFaceCache*, CSSFontSelector*);
 
     DECLARE_VIRTUAL_TRACE();
 
 private:
     static FontFaceSet* create(Document& document)
     {
         return new FontFaceSet(document);
     }
@@ skipping 58 matching lines @@
     HeapListHashSet<Member<FontFace>> m_nonCSSConnectedFaces;
 
     Member<AsyncMethodRunner<FontFaceSet>> m_asyncRunner;
 
     FontLoadHistogram m_histogram;
 };
 
 } // namespace blink
 
 #endif // FontFaceSet_h