Use leveldb_env::OpenDB() to open leveldb databases.

chrome/browser/android/history_report/delta_file_backend_leveldb.cc

 // Copyright 2015 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 "chrome/browser/android/history_report/delta_file_backend_leveldb.h"
 
 #include <inttypes.h>
 
 #include "base/files/file_util.h"
 #include "base/logging.h"
@@ skipping 77 matching lines @@
 }
 
 DeltaFileBackend::~DeltaFileBackend() {}
 
 bool DeltaFileBackend::Init() {
   leveldb::Options options;
   options.create_if_missing = true;
   options.max_open_files = 0;  // Use minimum number of files.
   options.comparator = leveldb_cmp_.get();
   std::string path = path_.value();
-  leveldb::DB* db = NULL;
-  leveldb::Status status = leveldb::DB::Open(options, path, &db);
+  leveldb::Status status = leveldb_env::OpenDB(options, path, &db_);
   if (status.IsCorruption()) {
     LOG(WARNING) << "Deleting possibly-corrupt database";
     base::DeleteFile(path_, true);
-    status = leveldb::DB::Open(options, path, &db);
+    status = leveldb_env::OpenDB(options, path, &db_);
   }
   if (status.ok()) {
-    CHECK(db);
-    db_.reset(db);
+    CHECK(db_);
     return true;
   }
   LOG(WARNING) << "Unable to open " << path_.value() << ": "
                << status.ToString();
   return false;
 }
 
 bool DeltaFileBackend::EnsureInitialized() {
   if (db_.get()) return true;
   return Init();
@@ skipping 114 matching lines @@
   leveldb::ReadOptions options;
   std::unique_ptr<leveldb::Iterator> db_it(db_->NewIterator(options));
   int num_entries = 0;
   for (db_it->SeekToFirst(); db_it->Valid(); db_it->Next()) num_entries++;
   dump.append(base::IntToString(num_entries));
   dump.append("]");
   return dump;
 }
 
 }  // namespace history_report