Don't restore in LayoutBlock::layout if clamping is delayed.

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

Index: third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.cpp
diff --git a/third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.cpp b/third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.cpp
index eb488b2f42003588ddf2af392cb6b0c7696bfc97..459200019d647bf7c82659f05c821a8f2de435c4 100644
--- a/third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.cpp
+++ b/third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.cpp
@@ -756,12 +756,11 @@ void PaintLayerScrollableArea::clampScrollPositionsAfterLayout()
         return;
     }
 
-    DoublePoint clamped = clampScrollPosition(scrollPositionDouble());
     // Restore before clamping because clamping clears the scroll anchor.
-    if (clamped != scrollPositionDouble() && shouldPerformScrollAnchoring()) {
+    if (shouldPerformScrollAnchoring())
         m_scrollAnchor.restore();
-        clamped = clampScrollPosition(scrollPositionDouble());
-    }
+
+    DoublePoint clamped = clampScrollPosition(scrollPositionDouble());
     if (clamped != scrollPositionDouble() || scrollOriginChanged())
         ScrollableArea::setScrollPosition(clamped, ProgrammaticScroll);