Update overlay scrollbars

cc/layers/scrollbar_layer_impl_base.cc

Index: cc/layers/scrollbar_layer_impl_base.cc
diff --git a/cc/layers/scrollbar_layer_impl_base.cc b/cc/layers/scrollbar_layer_impl_base.cc
index 362465be3b09f3d4b33d38f9404de2b55ae106b5..e9b9569e03ebf499850b1ee3ce3159aea4736382 100644
--- a/cc/layers/scrollbar_layer_impl_base.cc
+++ b/cc/layers/scrollbar_layer_impl_base.cc
@@ -66,6 +66,9 @@ void ScrollbarLayerImplBase::SetVerticalAdjust(float vertical_adjust) {
 }
 
 void ScrollbarLayerImplBase::SetVisibleToTotalLengthRatio(float ratio) {
+  if (!IsThumbResizable())
+    return;
+
   if (visible_to_total_length_ratio_ == ratio)
     return;
   visible_to_total_length_ratio_ = ratio;