Account for non-composited scroll offset of scrollbars.

third_party/WebKit/Source/core/paint/PaintInvalidationCapableScrollableArea.cpp

Index: third_party/WebKit/Source/core/paint/PaintInvalidationCapableScrollableArea.cpp
diff --git a/third_party/WebKit/Source/core/paint/PaintInvalidationCapableScrollableArea.cpp b/third_party/WebKit/Source/core/paint/PaintInvalidationCapableScrollableArea.cpp
index 56e49df56e4d84f92c83f66154d6d26d329950f2..4e5e28a73e807cc50050c701794568bbab29ef86 100644
--- a/third_party/WebKit/Source/core/paint/PaintInvalidationCapableScrollableArea.cpp
+++ b/third_party/WebKit/Source/core/paint/PaintInvalidationCapableScrollableArea.cpp
@@ -38,8 +38,13 @@ static LayoutRect scrollControlPaintInvalidationRect(
   // transform space than their contained box (the scrollbarPaintOffset
   // transform node).
   if (!paintInvalidationRect.isEmpty() &&
-      !RuntimeEnabledFeatures::slimmingPaintV2Enabled())
+      !RuntimeEnabledFeatures::slimmingPaintV2Enabled()) {
     context.mapLocalRectToPaintInvalidationBacking(box, paintInvalidationRect);
+
+    IntSize adjustment = box.scrollAdjustmentForPaintInvalidation(
+        *context.paintInvalidationContainer);
+    paintInvalidationRect.move(adjustment);
+  }
   return paintInvalidationRect;
 }