first-run: Pull IsBrowserAlreadyRunning() out of upgrade_util_win.h.

chrome/browser/browser_util_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_BROWSER_BROWSER_UTIL_WIN_H_
+#define CHROME_BROWSER_BROWSER_UTIL_WIN_H_
+#pragma once
+
+namespace browser_util {
+
+// Check if current chrome.exe is already running as a browser process by trying
+// to create a Global event with name same as full path of chrome.exe. This
+// method caches the handle to this event so on subsequent calls also it can
+// first close the handle and check for any other process holding the handle to
+// the event.
+bool IsBrowserAlreadyRunning();
+
+}  // namespace browser_util
+
+#endif  // CHROME_BROWSER_BROWSER_UTIL_WIN_H_