Detect change on the intersection of video and viewport.

third_party/WebKit/Source/core/dom/IntersectionObservation.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 IntersectionObservation_h
 #define IntersectionObservation_h
 
 #include "core/dom/DOMHighResTimeStamp.h"
-#include "platform/geometry/LayoutRect.h"
+#include "core/dom/IntersectionGeometry.h"
 #include "platform/heap/Handle.h"
 
 namespace blink {
 
 class Element;
 class IntersectionObserver;
 
 class IntersectionObservation final
     : public GarbageCollected<IntersectionObservation> {
  public:
-  IntersectionObservation(IntersectionObserver&,
-                          Element&,
-                          bool shouldReportRootBounds);
-
-  struct IntersectionGeometry {
-    LayoutRect targetRect;
-    LayoutRect intersectionRect;
-    LayoutRect rootRect;
-    bool doesIntersect;
-
-    IntersectionGeometry() : doesIntersect(false) {}
-  };
+  IntersectionObservation(
+      IntersectionObserver&,
+      Element&,
+      IntersectionGeometry::ReportRootBounds shouldReportRootBounds);
 
   IntersectionObserver& observer() const { return *m_observer; }
   Element* target() const { return m_target; }
   unsigned lastThresholdIndex() const { return m_lastThresholdIndex; }
   void setLastThresholdIndex(unsigned index) { m_lastThresholdIndex = index; }
-  bool shouldReportRootBounds() const { return m_shouldReportRootBounds; }
   void computeIntersectionObservations(DOMHighResTimeStamp);
   void disconnect();
   void clearRootAndRemoveFromTarget();
 
   DECLARE_TRACE();
 
  private:
-  void applyRootMargin(LayoutRect&) const;
-  void initializeGeometry(IntersectionGeometry&) const;
-  void initializeTargetRect(LayoutRect&) const;
-  void initializeRootRect(LayoutRect&) const;
-  void clipToRoot(IntersectionGeometry&) const;
-  void mapTargetRectToTargetFrameCoordinates(LayoutRect&) const;
-  void mapRootRectToRootFrameCoordinates(LayoutRect&) const;
-  void mapRootRectToTargetFrameCoordinates(LayoutRect&) const;
-  bool computeGeometry(IntersectionGeometry&) const;
-
   Member<IntersectionObserver> m_observer;
-
   WeakMember<Element> m_target;
 
-  unsigned m_shouldReportRootBounds : 1;
+  const unsigned m_shouldReportRootBounds : 1;
   unsigned m_lastThresholdIndex : 30;
 };
 
 }  // namespace blink
 
 #endif  // IntersectionObservation_h