Intersection Observer support for OOPIF

third_party/WebKit/Source/core/frame/RemoteFrameView.h

Index: third_party/WebKit/Source/core/frame/RemoteFrameView.h
diff --git a/third_party/WebKit/Source/core/frame/RemoteFrameView.h b/third_party/WebKit/Source/core/frame/RemoteFrameView.h
index 6f243f464f7c5972a4f090b18bb926f7df80110f..87694ce8a7c357ac076af67f4a65d755e72f7043 100644
--- a/third_party/WebKit/Source/core/frame/RemoteFrameView.h
+++ b/third_party/WebKit/Source/core/frame/RemoteFrameView.h
@@ -5,6 +5,7 @@
 #ifndef RemoteFrameView_h
 #define RemoteFrameView_h
 
+#include "core/dom/IntersectionObserver.h"
 #include "platform/Widget.h"
 #include "platform/geometry/IntRect.h"
 #include "platform/heap/Handle.h"
@@ -28,14 +29,10 @@ class RemoteFrameView final : public Widget {
   }
 
   void dispose() override;
-
   // Override to notify remote frame that its viewport size has changed.
   void frameRectsChanged() override;
-
   void invalidateRect(const IntRect&) override;
-
   void setFrameRect(const IntRect&) override;
-
   void hide() override;
   void show() override;
   void setParentVisible(bool) override;
@@ -45,11 +42,22 @@ class RemoteFrameView final : public Widget {
  private:
   explicit RemoteFrameView(RemoteFrame*);
 
+  void onViewportIntersectionChanged(
+      const HeapVector<Member<IntersectionObserverEntry>>&);
+  void startIntersectionObserver();
+  void stopIntersectionObserver();
+
   // The properties and handling of the cycle between RemoteFrame
   // and its RemoteFrameView corresponds to that between LocalFrame
   // and FrameView. Please see the FrameView::m_frame comment for
   // details.
   Member<RemoteFrame> m_remoteFrame;
+
+  // An IntersectionObserver is used to monitor the intersection of this
+  // frame with the viewport, which is then forwarded to the remote frame
+  // to enable viewport intersections there to work properly.
+  Member<IntersectionObserver> m_intersectionObserver;
+  IntRect m_lastViewportIntersection;
 };
 
 DEFINE_TYPE_CASTS(RemoteFrameView,