Revert of Remove CAPS

chrome/tools/crash_service/caps/process_singleton_win.h

+// 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.
+
+#ifndef CHROME_TOOLS_CRASH_SERVICE_CAPS_PROCESS_SINGLETON_WIN_H_
+#define CHROME_TOOLS_CRASH_SERVICE_CAPS_PROCESS_SINGLETON_WIN_H_
+
+#include <windows.h>
+
+#include "base/macros.h"
+
+namespace caps {
+// Uses a named mutex to make sure that only one process of
+// with this particular version is launched.
+class ProcessSingleton {
+public:
+  ProcessSingleton();
+  ~ProcessSingleton();
+  bool other_instance() const { return mutex_ == NULL; }
+
+private:
+  HANDLE mutex_;
+
+  DISALLOW_COPY_AND_ASSIGN(ProcessSingleton);
+};
+
+}  // namespace caps
+
+#endif  // CHROME_TOOLS_CRASH_SERVICE_CAPS_PROCESS_SINGLETON_WIN_H_
+