Ensure the Chromoting Host process eventually terminates when shut down.

remoting/host/shutdown_watchdog.cc

+// Copyright 2014 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 "remoting/host/shutdown_watchdog.h"
+
+#include <stdlib.h>  // For _exit() on Windows.
+
+#include "base/logging.h"
+
+#if defined(OS_POSIX)
+#include <unistd.h>
+#endif  // defined(OS_POSIX)
+
+namespace remoting {
+
+ShutdownWatchdog::ShutdownWatchdog(const base::TimeDelta& duration)
+    : base::Watchdog(duration, "Shutdown watchdog", true) {
+}
+
+void ShutdownWatchdog::SetExitCode(int exit_code) {
+  base::AutoLock lock(lock_);
+  exit_code_ = exit_code;
+}
+
+void ShutdownWatchdog::Alarm() {
+  // Holding a lock while calling _exit() might not be a safe thing to do, so
+  // make a local copy.
+  int exit_code;
+  {
+    base::AutoLock lock(lock_);
+    exit_code = exit_code_;
+  }
+
+  LOG(ERROR) << "Shutdown watchdog triggered, exiting with code " << exit_code;
+  _exit(exit_code);
+}
+
+}  // namespace remoting