Intersection Observer first draft

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

Index: third_party/WebKit/Source/core/layout/LayoutView.h
diff --git a/third_party/WebKit/Source/core/layout/LayoutView.h b/third_party/WebKit/Source/core/layout/LayoutView.h
index 6772b76e061f5d27b95485512cea58f1c990a9c9..fb87c448702553ca2b0bcf692293262208619416 100644
--- a/third_party/WebKit/Source/core/layout/LayoutView.h
+++ b/third_party/WebKit/Source/core/layout/LayoutView.h
@@ -41,6 +41,8 @@ namespace blink {
 class DeprecatedPaintLayerCompositor;
 class LayoutQuote;
 
+using IntersectionObserverTargetMap = HashMap<LayoutObject*, FloatRect>;
+
 // LayoutView is the root of the layout tree and the Document's LayoutObject.
 //
 // It corresponds to the CSS concept of 'initial containing block' (or ICB).
@@ -198,6 +200,10 @@ public:
     // It is very likely you do not want to call this method.
     void setShouldDoFullPaintInvalidationForViewAndAllDescendants();
 
+    void addIntersectionObserverTarget(LayoutObject*);
+    void removeIntersectionObserverTarget(LayoutObject*);
+    void computeIntersectionObservations(const FloatRect&);
+
 private:
     void mapLocalToContainer(const LayoutBoxModelObject* paintInvalidationContainer, TransformState&, MapCoordinatesFlags = ApplyContainerFlip, bool* wasFixed = nullptr, const PaintInvalidationState* = nullptr) const override;
 
@@ -260,6 +266,8 @@ private:
     unsigned m_hitTestCount;
     unsigned m_hitTestCacheHits;
     OwnPtrWillBePersistent<HitTestCache> m_hitTestCache;
+
+    IntersectionObserverTargetMap m_intersectionObserverTargets;
 };
 
 DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutView, isLayoutView());