Change single-interface mojo bindings to use SequencedTaskRunner.

components/leveldb/leveldb_service_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_service_impl.h"
 
 #include <memory>
 
 #include "base/memory/ptr_util.h"
+#include "base/single_thread_task_runner.h"
 #include "components/leveldb/env_mojo.h"
 #include "components/leveldb/leveldb_database_impl.h"
 #include "components/leveldb/public/cpp/util.h"
 #include "mojo/public/cpp/bindings/strong_associated_binding.h"
 #include "third_party/leveldatabase/env_chromium.h"
 #include "third_party/leveldatabase/src/helpers/memenv/memenv.h"
 #include "third_party/leveldatabase/src/include/leveldb/db.h"
 #include "third_party/leveldatabase/src/include/leveldb/env.h"
 #include "third_party/leveldatabase/src/include/leveldb/filter_policy.h"
 #include "third_party/leveldatabase/src/include/leveldb/slice.h"
@@ skipping 80 matching lines @@
   leveldb::Options options;
   // Register our directory with the file thread.
   LevelDBMojoProxy::OpaqueDir* dir =
       thread_->RegisterDirectory(std::move(directory));
   std::unique_ptr<MojoEnv> env_mojo(new MojoEnv(thread_, dir));
   options.env = env_mojo.get();
   callback.Run(LeveldbStatusToError(leveldb::DestroyDB(dbname, options)));
 }
 
 }  // namespace leveldb