Temporarily suppress element id collision DCHECK for SPV2

cc/trees/layer_tree_impl.cc

Index: cc/trees/layer_tree_impl.cc
diff --git a/cc/trees/layer_tree_impl.cc b/cc/trees/layer_tree_impl.cc
index a231d6f5728ae093705f735f91bb635a48e651eb..757510486dd206461fde97f34c6aad00907cfefd 100644
--- a/cc/trees/layer_tree_impl.cc
+++ b/cc/trees/layer_tree_impl.cc
@@ -554,7 +554,12 @@ void LayerTreeImpl::AddToElementMap(LayerImpl* layer) {
   LayerImpl* existing_layer = LayerByElementId(element_id);
   bool element_id_collision_detected =
       existing_layer && existing_layer != layer;
-  DCHECK(!element_id_collision_detected);
+
+  // TODO(pdr): Remove this suppression and always check for id collisions.
+  // This is a temporary suppression for SPV2 which generates unnecessary
+  // layers that collide. Remove once crbug.com/693693 is fixed.
+  if (!settings().use_layer_lists)
+    DCHECK(!element_id_collision_detected);
 #endif
 
   element_layers_map_[element_id] = layer->id();