Make updateLayoutAndStyleForPainting() O(N) in terms of frame number in LayoutView::hitTest()

Source/core/layout/LayoutView.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2006 Apple Computer, Inc.
  *
  * 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.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 34 matching lines @@
 // The root of the layout tree, corresponding to the CSS initial containing block.
 // It's dimensions match that of the logical viewport (which may be different from
 // the visible viewport in fixed-layout mode), and it is always at position (0,0)
 // relative to the document (and so isn't necessarily in view).
 class CORE_EXPORT LayoutView final : public LayoutBlockFlow {
 public:
     explicit LayoutView(Document*);
     virtual ~LayoutView();
     void willBeDestroyed() override;
 
+    // hitTest() will update layout and style first while hitTestNoLayoutAndStyleUpdate() does not.
     bool hitTest(HitTestResult&);
+    bool hitTestNoLayoutAndStyleUpdate(HitTestResult&);
 
     // Returns the total count of calls to HitTest, for testing.
     unsigned hitTestCount() const { return m_hitTestCount; }
     unsigned hitTestCacheHits() const { return m_hitTestCacheHits; }
 
     void clearHitTestCache() { m_hitTestCache->clear(); }
 
     virtual const char* name() const override { return "LayoutView"; }
 
     virtual bool isOfType(LayoutObjectType type) const override { return type == LayoutObjectLayoutView || LayoutBlockFlow::isOfType(type); }
@@ skipping 181 matching lines @@
             m_paintInvalidationState->m_cachedOffsetsEnabled = true;
     }
 private:
     const PaintInvalidationState* m_paintInvalidationState;
     bool m_didDisable;
 };
 
 } // namespace blink
 
 #endif // LayoutView_h