cc: Workaround invalid property tree state on Layers.

cc/layers/layer_impl.h

Index: cc/layers/layer_impl.h
diff --git a/cc/layers/layer_impl.h b/cc/layers/layer_impl.h
index 35a155de91bc02b43a06d8645f2f8bb4dfe61782..9bd1e49955c4f317cb9fdee06495d91eb7298930 100644
--- a/cc/layers/layer_impl.h
+++ b/cc/layers/layer_impl.h
@@ -448,6 +448,8 @@ class CC_EXPORT LayerImpl {
   }
   bool raster_even_if_not_drawn() const { return raster_even_if_not_drawn_; }
 
+  bool EnsureValidPropertyTreeIndices() const;

[enne (OOO), 2017/06/02 18:41:19]

bikeshed: functions called "Ensure" I expect to be void, in that they are either
asserting or silently making something valid.  This const function seems more
like a "HasValidPropertyTreeIndices".

[Khushal, 2017/06/02 18:47:03]

Done.

+
  protected:
   LayerImpl(LayerTreeImpl* layer_impl,
             int id,