Refactor the way PaintArtifactCompositor is attached and used.

third_party/WebKit/Source/core/frame/FrameView.h

 /*
    Copyright (C) 1997 Martin Jones (mjones@kde.org)
              (C) 1998 Waldo Bastian (bastian@kde.org)
              (C) 1998, 1999 Torben Weis (weis@kde.org)
              (C) 1999 Lars Knoll (knoll@kde.org)
              (C) 1999 Antti Koivisto (koivisto@kde.org)
    Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
 
    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Library General Public
@@ skipping 61 matching lines @@
 class LocalFrame;
 class KURL;
 class Node;
 class LayoutAnalyzer;
 class LayoutBox;
 class LayoutEmbeddedObject;
 class LayoutObject;
 class LayoutReplaced;
 class LayoutScrollbarPart;
 class LayoutView;
+class PaintArtifactCompositor;
 class PaintController;
 class PaintInvalidationState;
 class Page;
 class ScrollingCoordinator;
 class TracedValue;
 struct AnnotatedRegionValue;
 struct CompositedSelection;
 
 typedef unsigned long long DOMTimeStamp;
 
@@ skipping 854 matching lines @@
 
     // For testing.
     struct ObjectPaintInvalidation {
         String name;
         PaintInvalidationReason reason;
     };
     std::unique_ptr<Vector<ObjectPaintInvalidation>> m_trackedObjectPaintInvalidations;
 
     // For Slimming Paint v2 only.
     std::unique_ptr<PaintController> m_paintController;
+    std::unique_ptr<PaintArtifactCompositor> m_paintArtifactCompositor;
 };
 
 inline void FrameView::incrementVisuallyNonEmptyCharacterCount(unsigned count)
 {
     if (m_isVisuallyNonEmpty)
         return;
     m_visuallyNonEmptyCharacterCount += count;
     // Use a threshold value to prevent very small amounts of visible content from triggering didMeaningfulLayout.
     // The first few hundred characters rarely contain the interesting content of the page.
     static const unsigned visualCharacterThreshold = 200;
@@ skipping 11 matching lines @@
     if (m_visuallyNonEmptyPixelCount > visualPixelThreshold)
         setIsVisuallyNonEmpty();
 }
 
 DEFINE_TYPE_CASTS(FrameView, Widget, widget, widget->isFrameView(), widget.isFrameView());
 DEFINE_TYPE_CASTS(FrameView, ScrollableArea, scrollableArea, scrollableArea->isFrameView(), scrollableArea.isFrameView());
 
 } // namespace blink
 
 #endif // FrameView_h