Add database recovery for FileSystemDirectoryDatabase.

BUG=103018,116615
TEST='FileSystemDirectoryDatabaseTest.*'

Review URL: https://chromiumcodereview.appspot.com/9910005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@132369 0039d316-1c4b-4281-b951-d872f2087c98
11 files changed