Make PaintLayerClipper objects transient

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

Index: third_party/WebKit/Source/core/paint/PaintLayer.cpp
diff --git a/third_party/WebKit/Source/core/paint/PaintLayer.cpp b/third_party/WebKit/Source/core/paint/PaintLayer.cpp
index dd751063f6c27fa4ad42529642abd373693b81c7..0be1e7b196dd63c1a827dd19094fd6230a59c8b1 100644
--- a/third_party/WebKit/Source/core/paint/PaintLayer.cpp
+++ b/third_party/WebKit/Source/core/paint/PaintLayer.cpp
@@ -99,7 +99,7 @@ static CompositingQueryMode gCompositingQueryMode =
 
 struct SameSizeAsPaintLayer : DisplayItemClient {
     int bitFields;
-    void* pointers[8];
+    void* pointers[9];
     LayoutUnit layoutUnits[4];
     IntSize size;
     OwnPtrWillBePersistent<PaintLayerScrollableArea> scrollableArea;
@@ -108,9 +108,6 @@ struct SameSizeAsPaintLayer : DisplayItemClient {
         void* pointers[2];
     } ancestorCompositingInputs;
     struct {
-        void* pointers[2];
-    } clipper;
-    struct {
         IntSize size;
         void* pointer;
         LayoutRect rect;
@@ -173,7 +170,6 @@ PaintLayer::PaintLayer(LayoutBoxModelObject* layoutObject, PaintLayerType type)
     , m_last(0)
     , m_staticInlinePosition(0)
     , m_staticBlockPosition(0)
-    , m_clipper(*layoutObject)
 {
     updateStackingNode();
 
@@ -291,7 +287,7 @@ void PaintLayer::updateLayerPositionsAfterLayout()
 {
     TRACE_EVENT0("blink,benchmark", "PaintLayer::updateLayerPositionsAfterLayout");
 
-    m_clipper.clearClipRectsIncludingDescendants();
+    clipper().clearClipRectsIncludingDescendants();
     updateLayerPositionRecursive();
 
     {
@@ -368,7 +364,7 @@ bool PaintLayer::scrollsWithRespectTo(const PaintLayer* other) const
 
 void PaintLayer::updateLayerPositionsAfterOverflowScroll(const DoubleSize& scrollDelta)
 {
-    m_clipper.clearClipRectsIncludingDescendants();
+    clipper().clearClipRectsIncludingDescendants();
     updateLayerPositionsAfterScrollRecursive(scrollDelta, isPaintInvalidationContainer());
 }
 
@@ -418,9 +414,9 @@ void PaintLayer::updateTransform(const ComputedStyle* oldStyle, const ComputedSt
             m_rareData->transform.clear();
 
         // PaintLayers with transforms act as clip rects roots, so clear the cached clip rects here.
-        m_clipper.clearClipRectsIncludingDescendants();
+        clipper().clearClipRectsIncludingDescendants();
     } else if (hasTransform) {
-        m_clipper.clearClipRectsIncludingDescendants(AbsoluteClipRects);
+        clipper().clearClipRectsIncludingDescendants(AbsoluteClipRects);
     }
 
     updateTransformationMatrix();
@@ -1269,7 +1265,7 @@ void PaintLayer::removeOnlyThisLayer()
         }
     }
 
-    m_clipper.clearClipRectsIncludingDescendants();
+    clipper().clearClipRectsIncludingDescendants();
 
     PaintLayer* nextSib = nextSibling();
 
@@ -1311,7 +1307,7 @@ void PaintLayer::insertOnlyThisLayer()
         curr->moveLayers(m_parent, this);
 
     // Clear out all the clip rects.
-    m_clipper.clearClipRectsIncludingDescendants();
+    clipper().clearClipRectsIncludingDescendants();
 }
 
 // Returns the layer reached on the walk up towards the ancestor.