Made empty-cells property independent.

Made empty-cells property independent. Also updated
independent-inheritance-fast-path.html to include emptyCells.

Tested using independent-inheritance-fast-path.html.

BUG=628043

Review-Url: https://codereview.chromium.org/2555103003
Cr-Commit-Position: refs/heads/master@{#437434}
2 files changed