REGRESSION (r183300): Fixed elements flash when scrolling

[WebKit-https.git] / Source / WebCore / platform / graphics / ca / GraphicsLayerCA.h

diff --git a/Source/WebCore/platform/graphics/ca/GraphicsLayerCA.h b/Source/WebCore/platform/graphics/ca/GraphicsLayerCA.h
index 42112e9d968bf2ee0a06e68f76d61e5579ed7ea9..4f0e6a77b4afaec3ec68b6ce56591e06041d98f3 100644 (file)
--- a/Source/WebCore/platform/graphics/ca/GraphicsLayerCA.h
+++ b/Source/WebCore/platform/graphics/ca/GraphicsLayerCA.h
@@ -148,12 +148,9 @@ public:
     virtual FloatSize pixelAlignmentOffset() const override { return m_pixelAlignmentOffset; }
 
     struct CommitState {
-        bool ancestorHasTransformAnimation;
-        int treeDepth;
-        CommitState()
-            : ancestorHasTransformAnimation(false)
-            , treeDepth(0)
-        { }
+        int treeDepth { 0 };
+        bool ancestorHasTransformAnimation { false };
+        bool ancestorsAllowBackingStoreDetachment { true };
     };
     void recursiveCommitChanges(const CommitState&, const TransformState&, float pageScaleFactor = 1, const FloatPoint& positionRelativeToBase = FloatPoint(), bool affectedByPageScale = false);
 
@@ -197,6 +194,9 @@ private:
 
     virtual bool isCommittingChanges() const override { return m_isCommittingChanges; }
 
+    WEBCORE_EXPORT virtual void setAllowsBackingStoreDetachment(bool) override;
+    WEBCORE_EXPORT virtual bool allowsBackingStoreDetachment() const override { return m_allowsBackingStoreDetachment; }
+
     WEBCORE_EXPORT virtual double backingStoreMemoryEstimate() const override;
 
     WEBCORE_EXPORT virtual bool shouldRepaintOnSizeChange() const override;
@@ -293,7 +293,7 @@ private:
     const FloatRect& visibleRect() const { return m_visibleRect; }
     const FloatRect& coverageRect() const { return m_coverageRect; }
 
-    void setVisibleAndCoverageRects(const VisibleAndCoverageRects&);
+    void setVisibleAndCoverageRects(const VisibleAndCoverageRects&, bool allowBackingStoreDetachment);
     
     static FloatRect adjustTiledLayerVisibleRect(TiledBacking*, const FloatRect& oldVisibleRect, const FloatRect& newVisibleRect, const FloatSize& oldSize, const FloatSize& newSize);
 
@@ -510,6 +510,7 @@ private:
     ContentsLayerPurpose m_contentsLayerPurpose { NoContentsLayer };
     bool m_needsFullRepaint : 1;
     bool m_usingBackdropLayerType : 1;
+    bool m_allowsBackingStoreDetachment : 1;
     bool m_intersectsCoverageRect : 1;
 
     Color m_contentsSolidColor;