cc: Don't DCHECK for layers with non-invertible transforms.

cc/layers/picture_layer_impl.cc

Index: cc/layers/picture_layer_impl.cc
diff --git a/cc/layers/picture_layer_impl.cc b/cc/layers/picture_layer_impl.cc
index a2c951c5275a8952f1c595ec8d6104deab995393..be9798cd2065d96e673faa67a6b8581e6f6c7dd7 100644
--- a/cc/layers/picture_layer_impl.cc
+++ b/cc/layers/picture_layer_impl.cc
@@ -556,8 +556,18 @@ bool PictureLayerImpl::AreVisibleResourcesReady() const {
          ++iter) {
       if (should_force_uploads && *iter)
         layer_tree_impl()->tile_manager()->ForceTileUploadToComplete(*iter);
+
+      bool tile_ready = false;
       // A null tile (i.e. no recording) is considered "ready".
-      if (!*iter || iter->drawing_info().IsReadyToDraw())
+      if (!*iter) {
+        tile_ready = true;
+      } else if (iter->drawing_info().IsReadyToDraw()) {
+        tile_ready = true;
+      } else if (!iter->priority(PENDING_TREE).is_live) {
+        NOTREACHED() << "All tiles considered for activation should be live";
+        tile_ready = true;
+      }
+      if (tile_ready)
         missing_region.Subtract(iter.geometry_rect());
     }
   }