Load the metro driver dll at startup

chrome/app/metro_driver_win.h

+// Copyright (c) 2011 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.
+
+#ifndef CHROME_APP_METRO_DRIVER_WIN_H_
+#define CHROME_APP_METRO_DRIVER_WIN_H_
+
+#include <Windows.h>
+
+typedef int (*MainFn)(HINSTANCE instance);

[darin (slow to review), 2012/03/19 16:30:45]

nit: put this typedef inside the MetroDriver class.

+
+// Helper class to manage the metro driver dll. When present in the system,
+// the main process thread needs to call InitMetro(), normal execution of
+// chrome initialization will continue on a second thread while the main
+// thread will be servicing the metro message loop.
+class MetroDriver {
+ public:
+  MetroDriver();

[darin (slow to review), 2012/03/19 16:30:45]

nit: new line after here

+  // returns true if chrome is being launched in metro. If so we should
+  // call RunInMetro(). If not then we should just run chrome as usual.
+  bool in_metro_mode() const {  return (NULL != init_metro_fn_); }
+
+  // Enter the metro main function, which will only return when chrome metro
+  // is closed. Once metro has initialized, the dll creates a new thread
+  // which runs |main_fn|. This method returns when the chrome metro session
+  // is closed by the user.
+  int RunInMetro(HINSTANCE instance, MainFn main_fn);
+
+ private:
+  void* init_metro_fn_;
+};
+
+#endif  // CHROME_APP_METRO_DRIVER_WIN_H_