Intersection Observer support for OOPIF

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

Index: third_party/WebKit/Source/core/layout/LayoutView.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutView.cpp b/third_party/WebKit/Source/core/layout/LayoutView.cpp
index bc3ab68c3224a822d95c125fd48b2e22d2e619da..8dfaf9b20dfcc91e38f442b836d7af75357170b9 100644
--- a/third_party/WebKit/Source/core/layout/LayoutView.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutView.cpp
@@ -458,16 +458,25 @@ bool LayoutView::mapToVisualRectInAncestorSpace(
     rect.move(offsetForFixedPosition(true));
 
   // Apply our transform if we have one (because of full page zooming).
-  if (!ancestor && layer() && layer()->transform())
+  if (layer() && layer()->transform())
     rect = layer()->transform()->mapRect(rect);
 
-  ASSERT(ancestor);
   if (ancestor == this)
     return true;
 
   Element* owner = document().localOwner();
-  if (!owner)
+  if (!owner) {
+    // This is the case of a Frame with a remote parent.
+    if (!document().frame()->isMainFrame()) {
+      DCHECK(!ancestor);
+      LayoutRect viewportIntersectionRect(
+          frameView()->remoteViewportIntersection());
+      rect.intersect(viewportIntersectionRect);
+      if (rect.isEmpty())
+        return false;
+    }
     return true;
+  }
 
   if (LayoutBox* obj = owner->layoutBox()) {
     if (!(mode & InputIsInFrameCoordinates)) {