Remove the code added to make extensions compile on Aura Android.

chrome/browser/extensions/api/messaging/native_process_launcher_android.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/extensions/api/messaging/native_process_launcher.h"
-
-namespace extensions {
-
-// static
-base::FilePath NativeProcessLauncher::FindManifest(
-    const std::string& host_name,
-    bool allow_user_level_hosts,
-    std::string* error_message) {
-  return base::FilePath();
-}
-
-// static
-bool NativeProcessLauncher::LaunchNativeProcess(
-    const base::CommandLine& command_line,
-    base::Process* process,
-    base::File* read_file,
-    base::File* write_file) {
-  return false;
-}
-
-}  // namespace extensions