am 7a07f179: Merge change 20006 into donut

Merge commit '7a07f1797684597a3b932aa0b365049d3e7d6ff3'

* commit '7a07f1797684597a3b932aa0b365049d3e7d6ff3':
  After each test, the WebView cache should be cleared, otherwise the cache data will pile up.