Move all ancestor-dependent properties out of PaintLayer and into an aux. struct.

third_party/WebKit/Source/core/paint/PaintLayer.h

 /*
  * Copyright (C) 2003, 2009, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2013 Intel Corporation. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
@@ skipping 627 matching lines @@
     if (m_rareData || reasons != CompositingReasonNone)
       ensureRareData().potentialCompositingReasonsFromStyle = reasons;
   }
 
   bool hasStyleDeterminedDirectCompositingReasons() const {
     return potentialCompositingReasonsFromStyle() &
            CompositingReasonComboAllDirectStyleDeterminedReasons;
   }
 
   class AncestorDependentCompositingInputs {
-    DISALLOW_NEW();
-
    public:
-    AncestorDependentCompositingInputs() : clippingContainer(nullptr) {}
-
-    IntRect clippedAbsoluteBoundingBox;
-    IntRect unclippedAbsoluteBoundingBox;
-    const LayoutObject* clippingContainer;
-  };
-
-  class RareAncestorDependentCompositingInputs {
-   public:
-    RareAncestorDependentCompositingInputs()
+    AncestorDependentCompositingInputs()
         : opacityAncestor(nullptr),
           transformAncestor(nullptr),
           filterAncestor(nullptr),
           ancestorScrollingLayer(nullptr),
           nearestFixedPositionLayer(nullptr),
           scrollParent(nullptr),
-          clipParent(nullptr) {}
-
-    bool isDefault() const {
-      return !opacityAncestor && !transformAncestor && !filterAncestor &&
-             !ancestorScrollingLayer && !nearestFixedPositionLayer &&
-             !scrollParent && !clipParent;
-    }
+          clipParent(nullptr),
+          clippingContainer(nullptr) {}
 
     const PaintLayer* opacityAncestor;
     const PaintLayer* transformAncestor;
     const PaintLayer* filterAncestor;
 
     // The fist ancestor which can scroll. This is a subset of the
     // ancestorOverflowLayer chain where the scrolling layer is visible and
     // has a larger scroll content than its bounds.
     const PaintLayer* ancestorScrollingLayer;
     const PaintLayer* nearestFixedPositionLayer;
 
     // A scroll parent is a compositor concept. It's only needed in blink
     // because we need to use it as a promotion trigger. A layer has a
     // scroll parent if neither its compositor scrolling ancestor, nor any
     // other layer scrolled by this ancestor, is a stacking ancestor of this
     // layer. Layers with scroll parents must be scrolled with the main
     // scrolling layer by the compositor.
     const PaintLayer* scrollParent;
 
     // A clip parent is another compositor concept that has leaked into
     // blink so that it may be used as a promotion trigger. Layers with clip
     // parents escape the clip of a stacking tree ancestor. The compositor
     // needs to know about clip parents in order to circumvent its normal
     // clipping logic.
     const PaintLayer* clipParent;
+
+    IntRect clippedAbsoluteBoundingBox;
+    IntRect unclippedAbsoluteBoundingBox;
+    const LayoutObject* clippingContainer;
   };
 
   void setNeedsCompositingInputsUpdate();
   bool childNeedsCompositingInputsUpdate() const {
     return m_childNeedsCompositingInputsUpdate;
   }
   bool needsCompositingInputsUpdate() const {
     // While we're updating the compositing inputs, these values may differ.
     // We should never be asking for this value when that is the case.
     DCHECK(m_needsDescendantDependentCompositingInputsUpdate ==
            m_needsAncestorDependentCompositingInputsUpdate);
     return m_needsDescendantDependentCompositingInputsUpdate;
   }
 
   void updateAncestorOverflowLayer(const PaintLayer* ancestorOverflowLayer) {
     m_ancestorOverflowLayer = ancestorOverflowLayer;
   }
   void updateAncestorDependentCompositingInputs(
       const AncestorDependentCompositingInputs&,
-      const RareAncestorDependentCompositingInputs&,
       bool hasAncestorWithClipPath);
   void updateDescendantDependentCompositingInputs(
       bool hasDescendantWithClipPath,
       bool hasNonIsolatedDescendantWithBlendMode,
       bool hasRootScrollerAsDescendant);
   void didUpdateCompositingInputs();
 
   const IntRect& clippedAbsoluteBoundingBox() const {
     DCHECK(!m_needsAncestorDependentCompositingInputsUpdate);
-    return m_ancestorDependentCompositingInputs.clippedAbsoluteBoundingBox;
+    return m_ancestorDependentCompositingInputs->clippedAbsoluteBoundingBox;
   }
   const IntRect& unclippedAbsoluteBoundingBox() const {
     DCHECK(!m_needsAncestorDependentCompositingInputsUpdate);
-    return m_ancestorDependentCompositingInputs.unclippedAbsoluteBoundingBox;
+    return m_ancestorDependentCompositingInputs->unclippedAbsoluteBoundingBox;
   }
   const PaintLayer* opacityAncestor() const {
     DCHECK(!m_needsAncestorDependentCompositingInputsUpdate);
-    return m_rareAncestorDependentCompositingInputs
-               ? m_rareAncestorDependentCompositingInputs->opacityAncestor
+    return m_ancestorDependentCompositingInputs
+               ? m_ancestorDependentCompositingInputs->opacityAncestor
                : nullptr;
   }
   const PaintLayer* transformAncestor() const {
     DCHECK(!m_needsAncestorDependentCompositingInputsUpdate);
-    return m_rareAncestorDependentCompositingInputs
-               ? m_rareAncestorDependentCompositingInputs->transformAncestor
+    return m_ancestorDependentCompositingInputs
+               ? m_ancestorDependentCompositingInputs->transformAncestor
                : nullptr;
   }
   const PaintLayer* filterAncestor() const {
     DCHECK(!m_needsAncestorDependentCompositingInputsUpdate);
-    return m_rareAncestorDependentCompositingInputs
-               ? m_rareAncestorDependentCompositingInputs->filterAncestor
+    return m_ancestorDependentCompositingInputs
+               ? m_ancestorDependentCompositingInputs->filterAncestor
                : nullptr;
   }
   const LayoutObject* clippingContainer() const {
     DCHECK(!m_needsAncestorDependentCompositingInputsUpdate);
-    return m_ancestorDependentCompositingInputs.clippingContainer;
+    return m_ancestorDependentCompositingInputs->clippingContainer;
   }
   const PaintLayer* ancestorOverflowLayer() const {
     return m_ancestorOverflowLayer;
   }
   const PaintLayer* ancestorScrollingLayer() const {
     DCHECK(!m_needsAncestorDependentCompositingInputsUpdate);
-    return m_rareAncestorDependentCompositingInputs
-               ? m_rareAncestorDependentCompositingInputs
-                     ->ancestorScrollingLayer
+    return m_ancestorDependentCompositingInputs
+               ? m_ancestorDependentCompositingInputs->ancestorScrollingLayer
                : nullptr;
   }
   const PaintLayer* nearestFixedPositionLayer() const {
     DCHECK(!m_needsAncestorDependentCompositingInputsUpdate);
-    return m_rareAncestorDependentCompositingInputs
-               ? m_rareAncestorDependentCompositingInputs
-                     ->nearestFixedPositionLayer
+    return m_ancestorDependentCompositingInputs
+               ? m_ancestorDependentCompositingInputs->nearestFixedPositionLayer
                : nullptr;
   }
   const PaintLayer* scrollParent() const {
     DCHECK(!m_needsAncestorDependentCompositingInputsUpdate);
-    return m_rareAncestorDependentCompositingInputs
-               ? m_rareAncestorDependentCompositingInputs->scrollParent
+    return m_ancestorDependentCompositingInputs
+               ? m_ancestorDependentCompositingInputs->scrollParent
                : nullptr;
   }
   const PaintLayer* clipParent() const {
     DCHECK(!m_needsAncestorDependentCompositingInputsUpdate);
-    return m_rareAncestorDependentCompositingInputs
-               ? m_rareAncestorDependentCompositingInputs->clipParent
+    return m_ancestorDependentCompositingInputs
+               ? m_ancestorDependentCompositingInputs->clipParent
                : nullptr;
   }
   bool hasAncestorWithClipPath() const {
     DCHECK(!m_needsAncestorDependentCompositingInputsUpdate);
     return m_hasAncestorWithClipPath;
   }
   bool hasDescendantWithClipPath() const {
     DCHECK(!m_needsDescendantDependentCompositingInputsUpdate);
     return m_hasDescendantWithClipPath;
   }
@@ skipping 423 matching lines @@
   IntSize m_size;
 
   // Cached normal flow values for absolute positioned elements with static
   // left/top values.
   LayoutUnit m_staticInlinePosition;
   LayoutUnit m_staticBlockPosition;
 
   // The first ancestor having a non visible overflow.
   const PaintLayer* m_ancestorOverflowLayer;
 
-  AncestorDependentCompositingInputs m_ancestorDependentCompositingInputs;
-  std::unique_ptr<RareAncestorDependentCompositingInputs>
-      m_rareAncestorDependentCompositingInputs;
+  std::unique_ptr<AncestorDependentCompositingInputs>
+      m_ancestorDependentCompositingInputs;
 
   Persistent<PaintLayerScrollableArea> m_scrollableArea;
 
   mutable std::unique_ptr<ClipRectsCache> m_clipRectsCache;
 
   std::unique_ptr<PaintLayerStackingNode> m_stackingNode;
 
   IntSize m_previousScrollOffsetAccumulationForPainting;
   RefPtr<ClipRects> m_previousPaintingClipRects;
   LayoutRect m_previousPaintDirtyRect;
 
   std::unique_ptr<PaintLayerRareData> m_rareData;
 };
 
 }  // namespace blink
 
 #ifndef NDEBUG
 // Outside the WebCore namespace for ease of invocation from gdb.
 CORE_EXPORT void showLayerTree(const blink::PaintLayer*);
 CORE_EXPORT void showLayerTree(const blink::LayoutObject*);
 #endif
 
 #endif  // Layer_h