grid auto-fill doesn't account for container max-height

reduction:
```
<!DOCTYPE html><style>
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, 100px);
  grid-template-rows: repeat(auto-fill, 50px);
  max-width: 300px;
  max-height: 200px;
  background-color: gray;
}
</style><div class="grid"></div>
```