Don't call LayoutPart::widgetPositionsUpdated unnecessarily.

third_party/WebKit/Source/core/layout/LayoutPart.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Simon Hausmann <hausmann@kde.org>
  * Copyright (C) 2006, 2009 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 29 matching lines @@
     bool needsPreferredWidthsRecalculation() const final;
 
     bool nodeAtPoint(HitTestResult&, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset, HitTestAction) override;
 
     void ref() { ++m_refCount; }
     void deref();
 
     Widget* widget() const;
 
     void updateOnWidgetChange();
-    void updateWidgetPosition();
-    void widgetPositionsUpdated();
+    // Returns true if the geometry changed.
     bool updateWidgetGeometry();
 
+    // Notifies this object that all widgets on the page have been updated.
+    void widgetGeometriesUpdated();
+
     bool isLayoutPart() const final { return true; }
     virtual void paintContents(const PaintInfo&, const LayoutPoint&) const;
 
     bool isThrottledFrameView() const;
 
 protected:
     PaintLayerType layerTypeRequired() const override;
 
     void styleDidChange(StyleDifference, const ComputedStyle* oldStyle) final;
     void layout() override;
     void paint(const PaintInfo&, const LayoutPoint&) const override;
     CursorDirective getCursor(const LayoutPoint&, Cursor&) const final;
 
     // Overridden to invalidate the child frame if any.
     void invalidatePaintOfSubtreesIfNeeded(PaintInvalidationState&) override;
 
 private:
+    bool updateWidgetGeometryInternal();
     CompositingReasons additionalCompositingReasons() const override;
 
     void willBeDestroyed() final;
     void destroy() final;
 
     bool setWidgetGeometry(const LayoutRect&);
 
     bool nodeAtPointOverWidget(HitTestResult&, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset, HitTestAction);
 
     int m_refCount;
 };
 
 DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutPart, isLayoutPart());
 
 } // namespace blink
 
 #endif // LayoutPart_h