[C++11 Allowed Features] Declares a type-safe null pointer converting from NULL to nullptr in src/…

cc/layers/scrollbar_layer_impl_base.h

Index: cc/layers/scrollbar_layer_impl_base.h
diff --git a/cc/layers/scrollbar_layer_impl_base.h b/cc/layers/scrollbar_layer_impl_base.h
index 7d37acc4083985c18724246a7863953f64de14c7..a98c3ea5622284201580ae6b51e09126aa2af644 100644
--- a/cc/layers/scrollbar_layer_impl_base.h
+++ b/cc/layers/scrollbar_layer_impl_base.h
@@ -24,8 +24,8 @@ class CC_EXPORT ScrollbarLayerImplBase : public LayerImpl {
   }
 
   void SetScrollLayerAndClipLayerByIds(int scroll_layer_id, int clip_layer_id);
-  void ClearScrollLayer() { scroll_layer_ = NULL; }
-  void ClearClipLayer() { clip_layer_ = NULL; }
+  void ClearScrollLayer() { scroll_layer_ = nullptr; }
+  void ClearClipLayer() { clip_layer_ = nullptr; }
 
   float current_pos() const { return current_pos_; }
   bool SetCurrentPos(float current_pos);