mojo leveldb: Add support to use in memory database.

components/leveldb/leveldb_database_impl.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/leveldb/leveldb_database_impl.h"
 
 #include "base/rand_util.h"
 #include "components/leveldb/env_mojo.h"
 #include "components/leveldb/util.h"
 #include "mojo/common/common_type_converters.h"
@@ skipping 11 matching lines @@
   while ((new_id == 0) || (m.find(new_id) != m.end()))
     new_id = base::RandUint64();
 
   return new_id;
 }
 
 }  // namespace
 
 LevelDBDatabaseImpl::LevelDBDatabaseImpl(
     leveldb::LevelDBDatabaseRequest request,
-    scoped_ptr<MojoEnv> environment,
+    scoped_ptr<leveldb::Env> environment,
     scoped_ptr<leveldb::DB> db)
     : binding_(this, std::move(request)),
       environment_(std::move(environment)),
       db_(std::move(db)) {}
 
 LevelDBDatabaseImpl::~LevelDBDatabaseImpl() {
   for (auto& p : iterator_map_)
     delete p.second;
   for (auto& p : snapshot_map_)
     db_->ReleaseSnapshot(p.second);
@@ skipping 68 matching lines @@
     callback.Run(DatabaseError::INVALID_ARGUMENT, mojo::Array<uint8_t>());
 
   std::string value;
   leveldb::ReadOptions options;
   options.snapshot = it->second;
   leveldb::Status status = db_->Get(options, GetSliceFor(key), &value);
   callback.Run(LeveldbStatusToError(status), mojo::Array<uint8_t>::From(value));
 }
 
 }  // namespace leveldb