Add basic support for CAPS exe

chrome/tools/crash_service/caps/process_singleton_win.cc

+// 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 <windows.h>
+
+#include "chrome/tools/crash_service/caps/process_singleton_win.h"
+
+namespace caps {
+
+ProcessSingleton::ProcessSingleton() : mutex_(NULL) {

[scottmg, 2015/02/01 19:55:35]

NULL -> nullptr

+  auto mutex = ::CreateMutexW(nullptr, TRUE, L"CHROME.CAPS.V1");

[scottmg, 2015/02/01 19:55:35]

no W (are we not building as _UNICODE properly? if so, we should fix that)

[cpu_(ooo_6.6-7.5), 2015/02/03 02:44:58]

afaik we build ok, old habits die hard. changed.

+  if (!mutex)
+    return;
+  if (::GetLastError() == ERROR_ALREADY_EXISTS) {
+    ::CloseHandle(mutex);
+    return;
+  }
+  // We are now the single instance.
+  mutex_ = mutex;
+}
+
+ProcessSingleton::~ProcessSingleton() {
+  if (mutex_)
+    ::CloseHandle(mutex_);
+}
+
+}  // namespace caps
+