[RLS] Don't add to ScrollableAreaSet if the size is zero

third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.cpp

Index: third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.cpp
diff --git a/third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.cpp b/third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.cpp
index c3dcf5fc2a9a88ea94878a54c8eba71e1f94facf..675a4686b646b34e8084f8b079cb450656b6dd0a 100644
--- a/third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.cpp
+++ b/third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.cpp
@@ -1777,7 +1777,7 @@ void PaintLayerScrollableArea::UpdateScrollableAreaSet(bool has_overflow) {
     Box().SetNeedsPaintPropertyUpdate();
   }
 
-  if (scrolls_overflow_) {
+  if (scrolls_overflow_ && frame_view->IsScrollable()) {

[Srirama, 2017/05/05 06:21:22]

IsScrollable is calling GetScrollingReasons and that internally checks for 4
conditions. I think what is missing here is the first condition (If there is an
actual overflow). Ideally adding the first condition alone here should work but
it is not. Incase of NO-RLS flow contents_size is coming {0, 0} where as in RLS
flow, contents_size is coming as {1, 8}. So i think we need to debug more to
find out how size is coming as {1, 8}.

     DCHECK(CanHaveOverflowScrollbars(Box()));
     frame_view->AddScrollableArea(this);
   } else {