Split-out change for https://codereview.chromium.org/1145993002/ patch set 11

Source/core/layout/LayoutView.h

Index: Source/core/layout/LayoutView.h
diff --git a/Source/core/layout/LayoutView.h b/Source/core/layout/LayoutView.h
index 28da4a420a57b76320ce74f2b392d49eacbe3142..0cce7bf7914aea5301e0f25616983658d32aca07 100644
--- a/Source/core/layout/LayoutView.h
+++ b/Source/core/layout/LayoutView.h
@@ -173,6 +173,10 @@ public:
     void popLayoutState() { ASSERT(m_layoutState); m_layoutState = m_layoutState->next(); }
     virtual void invalidateTreeIfNeeded(PaintInvalidationState&) override final;
 
+protected:
+    virtual void styleDidChange(StyleDifference, const ComputedStyle* oldStyle) override;
+    virtual PaintInvalidationReason invalidatePaintIfNeeded(PaintInvalidationState&, const LayoutBoxModelObject& newPaintInvalidationContainer) override;
+
 private:
     virtual void mapLocalToContainer(const LayoutBoxModelObject* paintInvalidationContainer, TransformState&, MapCoordinatesFlags = ApplyContainerFlip, bool* wasFixed = 0, const PaintInvalidationState* = 0) const override;
     virtual const LayoutObject* pushMappingToContainer(const LayoutBoxModelObject* ancestorToStopAt, LayoutGeometryMap&) const override;
@@ -210,6 +214,13 @@ private:
 
     unsigned m_hitTestCount;
 
+    struct BackgroundPositioning {
+        TransformationMatrix transform;
+        LayoutSize borderBoxSize;
+        LayoutRect paddingBoxRect;
+        LayoutRect contentBoxRect;
+    } m_previousRootBackgroundPositioning;
+
     OwnPtrWillBePersistent<PendingSelection> m_pendingSelection;
 };