Remove const LayerImpl* from QuadSink

cc/layers/painted_scrollbar_layer_impl.cc

Index: cc/layers/painted_scrollbar_layer_impl.cc
diff --git a/cc/layers/painted_scrollbar_layer_impl.cc b/cc/layers/painted_scrollbar_layer_impl.cc
index ac6ce4a407dbee5717da365be9372c5a5a2bbb29..d17e6922860ed10d590bc6c52076dc570fbf4720 100644
--- a/cc/layers/painted_scrollbar_layer_impl.cc
+++ b/cc/layers/painted_scrollbar_layer_impl.cc
@@ -85,7 +85,7 @@ void PaintedScrollbarLayerImpl::AppendQuads(
 
   gfx::Rect thumb_quad_rect = ComputeThumbQuadRect();
   gfx::Rect visible_thumb_quad_rect =
-      quad_sink->UnoccludedContentRect(thumb_quad_rect, draw_transform());
+      quad_sink->UnoccludedContentRect(this, thumb_quad_rect, draw_transform());
 
   ResourceProvider::ResourceId thumb_resource_id =
       layer_tree_impl()->ResourceIdForUIResource(thumb_ui_resource_id_);
@@ -112,7 +112,7 @@ void PaintedScrollbarLayerImpl::AppendQuads(
 
   gfx::Rect track_quad_rect = content_bounds_rect;
   gfx::Rect visible_track_quad_rect =
-      quad_sink->UnoccludedContentRect(track_quad_rect, draw_transform());
+      quad_sink->UnoccludedContentRect(this, track_quad_rect, draw_transform());
   if (track_resource_id && !visible_track_quad_rect.IsEmpty()) {
     gfx::Rect opaque_rect(contents_opaque() ? track_quad_rect : gfx::Rect());
     const float opacity[] = {1.0f, 1.0f, 1.0f, 1.0f};