Left side vertical MD scrollbars grow toward right.

cc/layers/painted_scrollbar_layer.cc

Index: cc/layers/painted_scrollbar_layer.cc
diff --git a/cc/layers/painted_scrollbar_layer.cc b/cc/layers/painted_scrollbar_layer.cc
index 52368babd7d11f427163faf7095ea135f63fc1f7..164a75eef5bea2abb857fc66ec083dcff0874d6e 100644
--- a/cc/layers/painted_scrollbar_layer.cc
+++ b/cc/layers/painted_scrollbar_layer.cc
@@ -26,7 +26,8 @@ namespace cc {
 std::unique_ptr<LayerImpl> PaintedScrollbarLayer::CreateLayerImpl(
     LayerTreeImpl* tree_impl) {
   return PaintedScrollbarLayerImpl::Create(
-      tree_impl, id(), scrollbar_->Orientation());
+      tree_impl, id(), scrollbar_->Orientation(),
+      scrollbar_->IsLeftSideVerticalScrollbar(), scrollbar_->IsOverlay());
 }
 
 scoped_refptr<PaintedScrollbarLayer> PaintedScrollbarLayer::Create(