Monitor the intersection of video and viewport.

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

Index: third_party/WebKit/Source/core/dom/IntersectionObservation.h
diff --git a/third_party/WebKit/Source/core/dom/IntersectionObservation.h b/third_party/WebKit/Source/core/dom/IntersectionObservation.h
index cd87187c0a122f10d54e3965ed67354daa40e01e..36177ba112c9a1161dffae01c5b53c065b530ae5 100644
--- a/third_party/WebKit/Source/core/dom/IntersectionObservation.h
+++ b/third_party/WebKit/Source/core/dom/IntersectionObservation.h
@@ -14,12 +14,15 @@ namespace blink {
 class Element;
 class IntersectionObserver;
 
-class IntersectionObservation final
-    : public GarbageCollected<IntersectionObservation> {
+class IntersectionObservation
+    : public GarbageCollectedFinalized<IntersectionObservation> {
+  WTF_MAKE_NONCOPYABLE(IntersectionObservation);
+
  public:
   IntersectionObservation(IntersectionObserver&,
                           Element&,
                           bool shouldReportRootBounds);
+  virtual ~IntersectionObservation();
 
   struct IntersectionGeometry {
     LayoutRect targetRect;
@@ -35,12 +38,15 @@ class IntersectionObservation final
   unsigned lastThresholdIndex() const { return m_lastThresholdIndex; }
   void setLastThresholdIndex(unsigned index) { m_lastThresholdIndex = index; }
   bool shouldReportRootBounds() const { return m_shouldReportRootBounds; }
-  void computeIntersectionObservations(DOMHighResTimeStamp);
+  virtual void computeIntersectionObservations(DOMHighResTimeStamp);
   void disconnect();
   void clearRootAndRemoveFromTarget();
 
   DECLARE_TRACE();
 
+ protected:
+  bool computeGeometry(IntersectionGeometry&) const;
+
  private:
   void applyRootMargin(LayoutRect&) const;
   void initializeGeometry(IntersectionGeometry&) const;
@@ -50,7 +56,6 @@ class IntersectionObservation final
   void mapTargetRectToTargetFrameCoordinates(LayoutRect&) const;
   void mapRootRectToRootFrameCoordinates(LayoutRect&) const;
   void mapRootRectToTargetFrameCoordinates(LayoutRect&) const;
-  bool computeGeometry(IntersectionGeometry&) const;
 
   Member<IntersectionObserver> m_observer;
 
@@ -60,6 +65,19 @@ class IntersectionObservation final
   unsigned m_lastThresholdIndex : 30;
 };
 
+class ViewportIntersectionObservation final : public IntersectionObservation {
+  WTF_MAKE_NONCOPYABLE(ViewportIntersectionObservation);
+
+ public:
+  ViewportIntersectionObservation(IntersectionObserver&, Element&);
+  ~ViewportIntersectionObservation() final;
+
+  void computeIntersectionObservations(DOMHighResTimeStamp) final;
+
+ private:
+  LayoutRect m_lastIntersectRect;
+};
+
 }  // namespace blink
 
 #endif  // IntersectionObservation_h