Clear TopSites when deleting history.
Clear TopSites when deleting history.

Update top_sites_ right away, then request an update from the HistoryService.

TEST=TopSitesTest
BUG=none

Review URL: http://codereview.chromium.org/2964009

git-svn-id: http://src.chromium.org/svn/trunk/src@53048 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: c822b6b9c3361176393426b7bbd926860c84c8c4
meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser