Refactor scroll updates after layout.

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

Index: third_party/WebKit/Source/core/paint/PaintLayer.cpp
diff --git a/third_party/WebKit/Source/core/paint/PaintLayer.cpp b/third_party/WebKit/Source/core/paint/PaintLayer.cpp
index 16f625873668c322d216058212ebb91e6e3d0ab5..d00f1a585c8850301399534e78999af44a71eacb 100644
--- a/third_party/WebKit/Source/core/paint/PaintLayer.cpp
+++ b/third_party/WebKit/Source/core/paint/PaintLayer.cpp
@@ -855,6 +855,11 @@ void PaintLayer::UpdateLayerPosition() {
 #endif
 }
 
+void PaintLayer::UpdateScrollingAfterLayout() {
+  if (GetLayoutObject().HasOverflowClip())
+    scrollable_area_->UpdateAfterLayout();
+}
+
 TransformationMatrix PaintLayer::PerspectiveTransform() const {
   if (!GetLayoutObject().HasTransformRelatedProperty())
     return TransformationMatrix();