Revert of Move some scroll invalidations to the paint invalidation phase

Source/core/rendering/RenderLayerRepainter.cpp

Index: Source/core/rendering/RenderLayerRepainter.cpp
diff --git a/Source/core/rendering/RenderLayerRepainter.cpp b/Source/core/rendering/RenderLayerRepainter.cpp
index d6b23ecef98320bf91326d34eed6248ac53c29c6..62336f563659bdeb02247c95cbe44d53d43ab0b1 100644
--- a/Source/core/rendering/RenderLayerRepainter.cpp
+++ b/Source/core/rendering/RenderLayerRepainter.cpp
@@ -91,6 +91,20 @@
     }
 }
 
+LayoutRect RenderLayerRepainter::paintInvalidationRectIncludingNonCompositingDescendants() const
+{
+    LayoutRect paintInvalidationRect = m_renderer.previousPaintInvalidationRect();
+
+    for (RenderLayer* child = m_renderer.layer()->firstChild(); child; child = child->nextSibling()) {
+        // Don't include paint invalidation rects for composited child layers; they will paint themselves and have a different origin.
+        if (child->compositingState() == PaintsIntoOwnBacking || child->compositingState() == PaintsIntoGroupedBacking)
+            continue;
+
+        paintInvalidationRect.unite(child->paintInvalidator().paintInvalidationRectIncludingNonCompositingDescendants());
+    }
+    return paintInvalidationRect;
+}
+
 void RenderLayerRepainter::setBackingNeedsPaintInvalidationInRect(const LayoutRect& r)
 {
     // https://bugs.webkit.org/show_bug.cgi?id=61159 describes an unreproducible crash here,