cc: Apply contents scales to impl-side painting rasterization

cc/picture_pile_impl.h

Index: cc/picture_pile_impl.h
diff --git a/cc/picture_pile_impl.h b/cc/picture_pile_impl.h
index 807bcbf4c47a8deea9a8eddbda35bf6db67e57e5..93ac072ebe73094d60a7d9a351cbdbb9fed9447d 100644
--- a/cc/picture_pile_impl.h
+++ b/cc/picture_pile_impl.h
@@ -26,7 +26,11 @@ public:
   // Raster a subrect of this PicturePileImpl into the given canvas.
   // It's only safe to call paint on a cloned version.
   // It is assumed that contentsScale has already been applied to this canvas.
-  void Raster(SkCanvas* canvas, gfx::Rect rect, RenderingStats* stats);
+  void Raster(
+      SkCanvas* canvas,
+      gfx::Rect rect,
+      float contents_scale,
+      RenderingStats* stats);
 
 private:
   friend class PicturePile;