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

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

Index: third_party/WebKit/Source/core/paint/PaintLayer.h
diff --git a/third_party/WebKit/Source/core/paint/PaintLayer.h b/third_party/WebKit/Source/core/paint/PaintLayer.h
index 21f32a0bed73a086d96b347bfeae2a616dfc2bf3..e29a5c04b279a7847b9768250bd718309e509b33 100644
--- a/third_party/WebKit/Source/core/paint/PaintLayer.h
+++ b/third_party/WebKit/Source/core/paint/PaintLayer.h
@@ -645,32 +645,16 @@ class CORE_EXPORT PaintLayer : public DisplayItemClient {
   }
 
   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;
@@ -696,6 +680,10 @@ class CORE_EXPORT PaintLayer : public DisplayItemClient {
     // 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();
@@ -715,7 +703,6 @@ class CORE_EXPORT PaintLayer : public DisplayItemClient {
   }
   void updateAncestorDependentCompositingInputs(
       const AncestorDependentCompositingInputs&,
-      const RareAncestorDependentCompositingInputs&,
       bool hasAncestorWithClipPath);
   void updateDescendantDependentCompositingInputs(
       bool hasDescendantWithClipPath,
@@ -725,61 +712,59 @@ class CORE_EXPORT PaintLayer : public DisplayItemClient {
 
   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 {
@@ -1223,9 +1208,8 @@ class CORE_EXPORT PaintLayer : public DisplayItemClient {
   // 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;