Add ash perftest on background blur filter.

ash/test/ash_perftests.cc

+// Copyright 2017 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 "ash/test/ash_test_suite.h"
+#include "base/bind.h"
+#include "base/test/launcher/unit_test_launcher.h"
+#include "mojo/edk/embedder/embedder.h"
+
+int main(int argc, char** argv) {
+  ash::test::AshTestSuite test_suite(argc, argv);
+
+  mojo::edk::Init();
+  return base::LaunchUnitTestsSerially(
+      argc, argv,
+      base::Bind(&ash::test::AshTestSuite::Run, base::Unretained(&test_suite)));
+}