[Media Router] Conditionally enable mDNS on Windows.

chrome/browser/media/router/media_route_provider_util_win.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 "chrome/browser/media/router/media_route_provider_util_win.h"
+
+#include "base/files/file_path.h"
+#include "base/location.h"
+#include "base/path_service.h"
+#include "chrome/installer/util/browser_distribution.h"
+#include "chrome/installer/util/firewall_manager_win.h"
+#include "content/public/browser/browser_thread.h"
+
+namespace media_router {
+
+namespace {
+
+void DoCanFirewallUseLocalPorts(base::Callback<void(bool)> callback) {

[imcheng, 2016/03/25 06:26:30]

const ref input

[btolsch, 2016/03/25 18:57:04]

Done.

+  base::FilePath exe_path;
+  bool can_use_local_ports = false;
+  if (base::PathService::Get(base::FILE_EXE, &exe_path)) {
+    auto firewall_manager = installer::FirewallManager::Create(
+        BrowserDistribution::GetDistribution(), exe_path);
+    can_use_local_ports =
+        firewall_manager && firewall_manager->CanUseLocalPorts();
+  }
+  content::BrowserThread::PostTask(
+      content::BrowserThread::UI, FROM_HERE,
+      base::Bind(std::move(callback), can_use_local_ports));

[imcheng, 2016/03/25 06:26:30]

is the std::move necessary?

[btolsch, 2016/03/25 18:57:04]

A base::Callback is basically a pointer and a shared pointer. So passing by
value and moving is similar to passing by const ref and copying. I don't know
whether base::Bind takes advantage of rvalues of the function call though, and
since you don't like it I'll change it.

+}
+
+}  // namespace
+
+void CanFirewallUseLocalPorts(base::Callback<void(bool)> callback) {

[imcheng, 2016/03/25 06:26:30]

const ref input

[btolsch, 2016/03/25 18:57:04]

Done.

+  content::BrowserThread::PostTask(
+      content::BrowserThread::FILE, FROM_HERE,
+      base::Bind(&DoCanFirewallUseLocalPorts, std::move(callback)));

[imcheng, 2016/03/25 06:26:30]

is std::move necessary?

[btolsch, 2016/03/25 18:57:04]

See other comment.

+}
+
+}  // namespace media_router