Revert of [SyncFS] Introduce DatabaseWrapper class (https://codereview.chromium.org/
415033002/)
Reason for revert:
Broke compile on DrMemory bots.
Original issue's description:
> [SyncFS] Introduce DatabaseWrapper class.
>
> DatabaseWrapper class wraps leveldb::DB and leveldb::WriteBatch class.
> DatabaseWrapper has following features.
> - Simple interfaces for many usages.
> - I/O seems synchronous, with caching pending transactions on memory.
>
>
>
> BUG=347425
> TEST=./unit_tests --gtest_filter="DatabaseWrapper*"
>
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=286451
TBR=nhiroki@chromium.org,tzik@chromium.org,peria@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=398820
Review URL: https://codereview.chromium.org/
423423002
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@286483 0039d316-1c4b-4281-b951-d872f2087c98