Add theme support and auto-refresh when theme changes.
Fix most visited pages disappear when resize the window.
Be able to navigate to file:/// urls. (Note that the original "New Tab" page in Chrome 33.0.1750.117 can not do this.)
Fix bug that sometimes top sites are set before mostVisited array loads, which crashes and makes grid blank. The reason is that embeddedSearch.newTabPage.mostVisited takes time to load.
Add support to remove, undo and restore all the most visited pages.