Revert 271602 "Implementation of leveldb-backed PrefStore."
Caused failure:
LevelDBPrefStoreTest.GetMutableValue (run #1):
[ RUN ] LevelDBPrefStoreTest.GetMutableValue
Received signal 11 SEGV_MAPERR
000000000008
#0 0x00000345595e base::debug::StackTrace::StackTrace()
#1 0x000003455b78 base::debug::(anonymous namespace)::StackDumpSignalHandler()
#2 0x7f22d6faccb0 \u003Cunknown>
#3 0x000003473e6b base::JSONWriter::BuildJSONString()
#4 0x000003474aca base::JSONWriter::WriteWithOptions()
#5 0x0000028861d1 Serialize()
#6 0x000002888b6e LevelDBPrefStore::ReportValueChanged()
#7 0x0000016af06d LevelDBPrefStoreTest_GetMutableValue_Test::TestBody()
http://build.chromium.org/p/chromium.chromiumos/builders/Linux%20ChromiumOS%20Tests%20%281%29/builds/43483/steps/unit_tests/logs/GetMutableValue
> Implementation of leveldb-backed PrefStore.
>
> This is not hooked up yet, migration code from Json-backed stores is needed, among other things.
>
> BUG=362814
>
> Review URL: https://codereview.chromium.org/
169323003
TBR=dgrogan@chromium.org
Review URL: https://codereview.chromium.org/
290633013
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@271611 0039d316-1c4b-4281-b951-d872f2087c98