Fix lifetime of leveldb::MojoEnv instances.

components/leveldb/leveldb_database_impl.h

Index: components/leveldb/leveldb_database_impl.h
diff --git a/components/leveldb/leveldb_database_impl.h b/components/leveldb/leveldb_database_impl.h
index f621c5f50574e636bc474adb9f0ab7f07d069b83..3bb7123d20240b4cd785563339a3605f739acdda 100644
--- a/components/leveldb/leveldb_database_impl.h
+++ b/components/leveldb/leveldb_database_impl.h
@@ -14,11 +14,16 @@
 
 namespace leveldb {
 
+class MojoEnv;
+
 // The backing to a database object that we pass to our called.
 class LevelDBDatabaseImpl : public mojom::LevelDBDatabase {
  public:
-  LevelDBDatabaseImpl(std::unique_ptr<leveldb::Env> environment,
-                      std::unique_ptr<leveldb::DB> db);
+  LevelDBDatabaseImpl(std::unique_ptr<Env> owned_environment,
+                      std::unique_ptr<DB> db);
+  LevelDBDatabaseImpl(MojoEnv* environment,
+                      std::string directory_prefix,
+                      std::unique_ptr<DB> db);
   ~LevelDBDatabaseImpl() override;
 
   // Overridden from LevelDBDatabase:
@@ -68,8 +73,10 @@ class LevelDBDatabaseImpl : public mojom::LevelDBDatabase {
   leveldb::Status DeletePrefixedHelper(const leveldb::Slice& key_prefix,
                                        leveldb::WriteBatch* batch);
 
-  std::unique_ptr<leveldb::Env> environment_;
-  std::unique_ptr<leveldb::DB> db_;
+  std::unique_ptr<Env> owned_environment_;
+  MojoEnv* environment_ = nullptr;
+  std::string directory_prefix_;
+  std::unique_ptr<DB> db_;
 
   std::map<base::UnguessableToken, const Snapshot*> snapshot_map_;