Roll leveldb to r77.
Biggest change for chromium is no longer using .sst as the sstable file
extension. The .sst extension caused windows system restore to corrupt
databases (error message: Corruption: 1 missing files; e.g...).
The only other change that could affect chromium is a bugfix, where
changing directions on an iterator could yield the wrong value.
(https://code.google.com/p/leveldb/issues/detail?id=200)
BUG=261623
R=jsbell@chromium.org
Review URL: https://codereview.chromium.org/
23976008
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@224433 0039d316-1c4b-4281-b951-d872f2087c98