Refactor IntersectionGeometry class and move it to core/layout.

third_party/WebKit/Source/core/dom/IntersectionGeometry.h

-// Copyright 2016 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef IntersectionGeometry_h
-#define IntersectionGeometry_h
-
-#include "platform/Length.h"
-#include "platform/geometry/LayoutRect.h"
-#include "platform/heap/Handle.h"
-#include "wtf/Vector.h"
-
-namespace blink {
-
-class Node;
-class Element;
-class LayoutObject;
-
-class IntersectionGeometry final
-    : public GarbageCollectedFinalized<IntersectionGeometry> {
- public:
-  enum ReportRootBounds {
-    kShouldReportRootBounds,
-    kShouldNotReportRootBounds,
-  };
-
-  IntersectionGeometry(Node* root,
-                       Element* target,
-                       const Vector<Length>& rootMargin,
-                       ReportRootBounds shouldReportRootBounds);
-  ~IntersectionGeometry();
-
-  void computeGeometry();
-  LayoutRect targetRect() const { return m_targetRect; }
-  LayoutRect intersectionRect() const { return m_intersectionRect; }
-  LayoutRect rootRect() const { return m_rootRect; }
-  bool doesIntersect() const { return m_doesIntersect; }
-
-  IntRect intersectionIntRect() const {
-    return pixelSnappedIntRect(m_intersectionRect);
-  }
-
-  IntRect targetIntRect() const { return pixelSnappedIntRect(m_targetRect); }
-
-  IntRect rootIntRect() const { return pixelSnappedIntRect(m_rootRect); }
-
-  DECLARE_TRACE();
-
- private:
-  void initializeGeometry();
-  void initializeTargetRect();
-  void initializeRootRect();
-  void clipToRoot();
-  void mapTargetRectToTargetFrameCoordinates();
-  void mapRootRectToRootFrameCoordinates();
-  void mapRootRectToTargetFrameCoordinates();
-  Element* root() const;
-  LayoutObject* getRootLayoutObject() const;
-  void applyRootMargin();
-
-  Member<Node> m_root;
-  Member<Element> m_target;
-  const Vector<Length> m_rootMargin;
-  const ReportRootBounds m_shouldReportRootBounds;
-  LayoutRect m_targetRect;
-  LayoutRect m_intersectionRect;
-  LayoutRect m_rootRect;
-  bool m_doesIntersect = false;
-};
-
-}  // namespace blink
-
-#endif  // IntersectionGeometry_h