arc: ARC loading progress should not be shown when started from OOBE.

chrome/browser/chromeos/arc/arc_session_manager_data_removed_waiter.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 "chrome/browser/chromeos/arc/arc_session_manager_data_removed_waiter.h"
+
+#include "base/run_loop.h"
+
+namespace arc {
+
+ArcSessionManagerDataRemovedWaiter::ArcSessionManagerDataRemovedWaiter() {
+  DCHECK(ArcSessionManager::Get());
+  ArcSessionManager::Get()->AddObserver(this);
+}
+
+ArcSessionManagerDataRemovedWaiter::~ArcSessionManagerDataRemovedWaiter() {
+  ArcSessionManager::Get()->RemoveObserver(this);
+}
+
+void ArcSessionManagerDataRemovedWaiter::Wait() {
+  run_loop_.reset(new base::RunLoop);

[hidehiko, 2017/01/30 10:12:35]

run_loop_ = base::MakeUnique<RunLoop>();
cf) Please refer our style guide Luis sent.

[khmel, 2017/01/31 02:47:08]

Done.

+  run_loop_->Run();
+  run_loop_.reset();
+}
+
+void ArcSessionManagerDataRemovedWaiter::OnArcDataRemoved() {
+  if (!run_loop_)
+    return;
+  run_loop_->Quit();
+}
+
+}  // namespace arc