Add flag to show toolkit-views dialogs on Mac, start with HTTP-Auth.

chrome/browser/ui/browser_dialogs_mac.cc

Index: chrome/browser/ui/browser_dialogs_mac.cc
diff --git a/chrome/browser/ui/browser_dialogs_mac.cc b/chrome/browser/ui/browser_dialogs_mac.cc
new file mode 100644
index 0000000000000000000000000000000000000000..872615499b7d2a4bfe65788079cf7c40590f2863
--- /dev/null
+++ b/chrome/browser/ui/browser_dialogs_mac.cc
@@ -0,0 +1,17 @@
+// 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/ui/browser_dialogs.h"
+
+#include "base/command_line.h"
+#include "chrome/common/chrome_switches.cc"
+
+namespace chrome {
+
+bool ToolkitViewsDialogsEnabled() {
+  return base::CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kEnableToolkitViewsDialogsMac);
+}
+
+}  // namespace chrome