Cleanup ScrollableArea scrolling API

Source/core/paint/DeprecatedPaintLayerScrollableArea.cpp

Index: Source/core/paint/DeprecatedPaintLayerScrollableArea.cpp
diff --git a/Source/core/paint/DeprecatedPaintLayerScrollableArea.cpp b/Source/core/paint/DeprecatedPaintLayerScrollableArea.cpp
index aec03b25f5885a757bafcb1410029f1ef6786655..dd2900949de8b2f6a450b9b5fdfcdea11810ccad 100644
--- a/Source/core/paint/DeprecatedPaintLayerScrollableArea.cpp
+++ b/Source/core/paint/DeprecatedPaintLayerScrollableArea.cpp
@@ -634,10 +634,7 @@ void DeprecatedPaintLayerScrollableArea::updateAfterLayout()
 
     if (originalScrollOffset != adjustedScrollOffset()) {
         DoublePoint origin(scrollOrigin());
-
-        // Call the base version here since calling this class' version will early because the
-        // offset itself hasn't changed, the scroll origin has.
-        ScrollableArea::setScrollPosition(-origin + adjustedScrollOffset(), ProgrammaticScroll);
+        scrollPositionChanged(-origin + adjustedScrollOffset(), ProgrammaticScroll);
     }
 
     bool hasHorizontalOverflow = this->hasHorizontalOverflow();