Remove background obscuration checks.

sky/engine/core/rendering/RenderLayer.h

Index: sky/engine/core/rendering/RenderLayer.h
diff --git a/sky/engine/core/rendering/RenderLayer.h b/sky/engine/core/rendering/RenderLayer.h
index 02ba14aa6f1a6ea779b8a8519e01250189be7bc4..01cbcc9d1d9d0993b370bba31df43975a96c9e44 100644
--- a/sky/engine/core/rendering/RenderLayer.h
+++ b/sky/engine/core/rendering/RenderLayer.h
@@ -147,11 +147,6 @@ public:
     RenderLayer* enclosingFilterLayer(IncludeSelfOrNot = IncludeSelf) const;
     bool hasAncestorWithFilterOutsets() const;
 
-    bool canUseConvertToLayerCoords() const
-    {
-        return !renderer()->hasTransform();
-    }
-
     void convertToLayerCoords(const RenderLayer* ancestorLayer, LayoutPoint&) const;
     void convertToLayerCoords(const RenderLayer* ancestorLayer, LayoutRect&) const;
 
@@ -224,10 +219,6 @@ public:
 
     bool paintsWithTransform() const;
 
-    // Returns true if background phase is painted opaque in the given rect.
-    // The query rect is given in local coordinates.
-    bool backgroundIsKnownToBeOpaqueInRect(const LayoutRect&) const;
-
     bool containsDirtyOverlayScrollbars() const { return m_containsDirtyOverlayScrollbars; }
     void setContainsDirtyOverlayScrollbars(bool dirtyScrollbars) { m_containsDirtyOverlayScrollbars = dirtyScrollbars; }
 
@@ -452,8 +443,6 @@ private:
 
     bool hitTestContents(const HitTestRequest&, HitTestResult&, const LayoutRect& layerBounds, const HitTestLocation&, HitTestFilter) const;
 
-    bool childBackgroundIsKnownToBeOpaqueInRect(const LayoutRect&) const;
-
     bool shouldBeSelfPaintingLayer() const;
 
     // FIXME: We should only create the stacking node if needed.