cc: Make PaintedScrollbarLayer not use ContentsScalingLayer

cc/layers/layer_impl.cc

Index: cc/layers/layer_impl.cc
diff --git a/cc/layers/layer_impl.cc b/cc/layers/layer_impl.cc
index f74228bdacf694cca1ac36e0c2503da2ba4fc510..1f557327050fcf6744e0dde3ef81a19c34f9c6c5 100644
--- a/cc/layers/layer_impl.cc
+++ b/cc/layers/layer_impl.cc
@@ -261,6 +261,23 @@ void LayerImpl::PopulateSharedQuadState(SharedQuadState* state) const {
       draw_properties_.blend_mode, sorting_context_id_);
 }
 
+void LayerImpl::PopulateScaledSharedQuadState(SharedQuadState* state,
+                                              float scale) const {
+  gfx::Transform scaled_draw_transform =
+      draw_properties_.target_space_transform;
+  scaled_draw_transform.Scale(SK_MScalar1 / scale, SK_MScalar1 / scale);
+  gfx::Size scaled_content_bounds =
+      gfx::ToCeiledSize(gfx::ScaleSize(bounds(), scale));
+  gfx::Rect scaled_visible_content_rect =
+      gfx::ScaleToEnclosingRect(visible_content_rect(), scale);
+  scaled_visible_content_rect.Intersect(gfx::Rect(scaled_content_bounds));
+
+  state->SetAll(scaled_draw_transform, scaled_content_bounds,
+                scaled_visible_content_rect, draw_properties().clip_rect,
+                draw_properties().is_clipped, draw_properties().opacity,
+                draw_properties().blend_mode, sorting_context_id_);
+}
+
 bool LayerImpl::WillDraw(DrawMode draw_mode,
                          ResourceProvider* resource_provider) {
   // WillDraw/DidDraw must be matched.