Tie scroll anchoring adjustments to frame lifecycle instead of layout.

third_party/WebKit/Source/core/frame/FrameView.h

Index: third_party/WebKit/Source/core/frame/FrameView.h
diff --git a/third_party/WebKit/Source/core/frame/FrameView.h b/third_party/WebKit/Source/core/frame/FrameView.h
index d8f183533b304cbc72c827789d3e7ae11255013c..b3599a1a4aff012cc36dcd6a98b24b14d8e39357 100644
--- a/third_party/WebKit/Source/core/frame/FrameView.h
+++ b/third_party/WebKit/Source/core/frame/FrameView.h
@@ -722,6 +722,8 @@ class CORE_EXPORT FrameView final
   ScrollAnchor* scrollAnchor() override { return &m_scrollAnchor; }
   void clearScrollAnchor();
   bool shouldPerformScrollAnchoring() const override;
+  void enqueueScrollAnchoringAdjustment(ScrollableArea*);
+  void performScrollAnchoringAdjustments();
 
   // For PaintInvalidator temporarily. TODO(wangxianzhu): Move into
   // PaintInvalidator.
@@ -1058,6 +1060,9 @@ class CORE_EXPORT FrameView final
   DocumentLifecycle::LifecycleState m_currentUpdateLifecyclePhasesTargetState;
 
   ScrollAnchor m_scrollAnchor;
+  using AnchoringAdjustmentQueue =
+      HeapLinkedHashSet<WeakMember<ScrollableArea>>;
+  AnchoringAdjustmentQueue m_anchoringAdjustmentQueue;
 
   bool m_needsScrollbarsUpdate;
   bool m_suppressAdjustViewSize;