[RootLayerScrolls] Fix frame scrolling layer in ScrollingCoordinator

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 9827ef4f23b74bfe435803879bb92928c3035e96..8e915fe9217001f80e3026f43383a77d7b151ba8 100644
--- a/third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.cpp
+++ b/third_party/WebKit/Source/core/paint/PaintLayerScrollableArea.cpp
@@ -565,6 +565,10 @@ IntSize PaintLayerScrollableArea::contentsSize() const {
   return IntSize(pixelSnappedScrollWidth(), pixelSnappedScrollHeight());
 }
 
+bool PaintLayerScrollableArea::isScrollable() const {
+  return scrollsOverflow();
+}
+
 IntPoint PaintLayerScrollableArea::lastKnownMousePosition() const {
   return box().frame() ? box().frame()->eventHandler().lastKnownMousePosition()
                        : IntPoint();