Convert //cc from scoped_ptr to std::unique_ptr.

cc/layers/painted_scrollbar_layer_impl.h

Index: cc/layers/painted_scrollbar_layer_impl.h
diff --git a/cc/layers/painted_scrollbar_layer_impl.h b/cc/layers/painted_scrollbar_layer_impl.h
index 8ea06ab5d8c03f13a1b8fbb61281c502cac6721c..10c6ba63af912e67a446de141e1d06a8903978b6 100644
--- a/cc/layers/painted_scrollbar_layer_impl.h
+++ b/cc/layers/painted_scrollbar_layer_impl.h
@@ -18,14 +18,12 @@ class ScrollView;
 
 class CC_EXPORT PaintedScrollbarLayerImpl : public ScrollbarLayerImplBase {
  public:
-  static scoped_ptr<PaintedScrollbarLayerImpl> Create(
-      LayerTreeImpl* tree_impl,
-      int id,
-      ScrollbarOrientation orientation);
+  static std::unique_ptr<PaintedScrollbarLayerImpl>
+  Create(LayerTreeImpl* tree_impl, int id, ScrollbarOrientation orientation);
   ~PaintedScrollbarLayerImpl() override;
 
   // LayerImpl implementation.
-  scoped_ptr<LayerImpl> CreateLayerImpl(LayerTreeImpl* tree_impl) override;
+  std::unique_ptr<LayerImpl> CreateLayerImpl(LayerTreeImpl* tree_impl) override;
   void PushPropertiesTo(LayerImpl* layer) override;
 
   bool WillDraw(DrawMode draw_mode,