Intersection Observer first draft

third_party/WebKit/Source/core/layout/LayoutObject.cpp

Index: third_party/WebKit/Source/core/layout/LayoutObject.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutObject.cpp b/third_party/WebKit/Source/core/layout/LayoutObject.cpp
index 80565df0ef762904c649c481e51d244adfde82f2..a276365074fcc62eec7c0a20d231695b47fd1241 100644
--- a/third_party/WebKit/Source/core/layout/LayoutObject.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutObject.cpp
@@ -2468,6 +2468,9 @@ void LayoutObject::willBeDestroyed()
 
     if (frameView())
         setIsSlowRepaintObject(false);
+
+    if (view() && hasIntersectionObserver())
+        view()->removeIntersectionObserverTarget(this);
 }
 
 void LayoutObject::insertedIntoTree()
@@ -2496,6 +2499,9 @@ void LayoutObject::insertedIntoTree()
 
     if (LayoutFlowThread* flowThread = flowThreadContainingBlock())
         flowThread->flowThreadDescendantWasInserted(this);
+
+    if (view() && hasIntersectionObserver())
+        view()->addIntersectionObserverTarget(this);
 }
 
 void LayoutObject::willBeRemovedFromTree()
@@ -2525,6 +2531,9 @@ void LayoutObject::willBeRemovedFromTree()
     // Update cached boundaries in SVG layoutObjects if a child is removed.
     if (parent()->isSVG())
         parent()->setNeedsBoundariesUpdate();
+
+    if (view() && hasIntersectionObserver())
+        view()->removeIntersectionObserverTarget(this);
 }
 
 void LayoutObject::removeFromLayoutFlowThread()