Migrate --enable-arc and --arc-available part 1.

components/arc/arc_util.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 "components/arc/arc_util.h"
+
+#include "base/command_line.h"
+#include "base/feature_list.h"
+#include "chromeos/chromeos_switches.h"
+
+namespace arc {
+
+namespace {
+
+// This is for finch. See also crbug.com/633704 for details.
+// TODO(hidehiko): More comments of the intention how this works, when
+// we unify the commandline flags.
+const base::Feature kEnableArcFeature{"EnableARC",
+                                      base::FEATURE_DISABLED_BY_DEFAULT};
+
+}  // namespace
+
+bool IsArcAvailable() {
+  const auto* command_line = base::CommandLine::ForCurrentProcess();
+  // TODO(hidehiko): Unify --enable-arc and --arc-available flags.

[Yusuke Sato, 2017/01/24 19:02:44]

What about adding something like this?

 // If switches::kEnableArc is set, the device is officially supported to run
 // ARC. If it is not, but switches::kArcAvailable is set, ARC is installed
 // but is not allowed to run unless |kEnableArcFeature| is true.

[hidehiko, 2017/01/25 17:54:46]

Done.

+  return command_line->HasSwitch(chromeos::switches::kEnableArc) ||
+         (command_line->HasSwitch(chromeos::switches::kArcAvailable) &&
+          base::FeatureList::IsEnabled(kEnableArcFeature));
+}
+
+}  // namespace arc