SnapManager implementation using V8 Extras - {WIP}

third_party/WebKit/Source/core/page/scrolling/SnapCoordinator.h

Index: third_party/WebKit/Source/core/page/scrolling/SnapCoordinator.h
diff --git a/third_party/WebKit/Source/core/page/scrolling/SnapCoordinator.h b/third_party/WebKit/Source/core/page/scrolling/SnapCoordinator.h
index aca6905209fda100ea972fef3eafeb874bafb36c..b435e82c6ea748ab18eca145e7b4097af62a8610 100644
--- a/third_party/WebKit/Source/core/page/scrolling/SnapCoordinator.h
+++ b/third_party/WebKit/Source/core/page/scrolling/SnapCoordinator.h
@@ -17,6 +17,12 @@ class ContainerNode;
 class Element;
 class LayoutBox;
 struct LengthPoint;
+class SnapManager;
+
+struct SnapOffsets {
+    Vector<double> horizontal;
+    Vector<double> vertical;
+};
 
 // Snap Coordinator keeps track of snap containers and all of their associated
 // snap areas. It also contains the logic to generate the list of valid snap
@@ -33,15 +39,22 @@ struct LengthPoint;
 // For more information see spec: https://drafts.csswg.org/css-snappoints/
 class CORE_EXPORT SnapCoordinator final : public GarbageCollectedFinalized<SnapCoordinator> {
     WTF_MAKE_NONCOPYABLE(SnapCoordinator);
-
 public:
-    static SnapCoordinator* create();
+    class Client {
+    public:
+        virtual void didUpdateSnapOffsets(const LayoutBox&, SnapOffsets) = 0;
+    };
+
+    static SnapCoordinator* create(Client*);
     ~SnapCoordinator();
     DEFINE_INLINE_TRACE() {}
 
     void snapContainerDidChange(LayoutBox&, ScrollSnapType);
     void snapAreaDidChange(LayoutBox&, const Vector<LengthPoint>& snapCoordinates);
 
+    void notifyLayoutUpdated();
+    void clear();
+
 #ifndef NDEBUG
     void showSnapAreaMap();
     void showSnapAreasFor(const LayoutBox*);
@@ -49,13 +62,18 @@ public:
 
 private:
     friend class SnapCoordinatorTest;
-    explicit SnapCoordinator();
+    explicit SnapCoordinator(Client*);
 
     Vector<double> snapOffsets(const ContainerNode&, ScrollbarOrientation);
 
     HashSet<const LayoutBox*> m_snapContainers;
+    HashMap<const LayoutBox*, SnapOffsets> m_offsetMap;
+    Client* m_client;
+
 };
 
+bool operator==(const SnapOffsets&, const SnapOffsets&);
+
 } // namespace blink
 
 #endif // SnapCoordinator_h