Have content/ create and destroy its own threads.

content/public/browser/browser_shutdown.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 CONTENT_PUBLIC_BROWSER_BROWSER_SHUTDOWN_H_
+#define CONTENT_PUBLIC_BROWSER_BROWSER_SHUTDOWN_H_
+#pragma once
+
+#include "content/common/content_export.h"
+
+namespace content {
+
+// This can be used for as-fast-as-possible shutdown, in cases where
+// time for shutdown is limited and we just need to write out as much
+// data as possible before our time runs out.
+//
+// This causes the shutdown sequence embodied by
+// BrowserMainParts::PostMainMessageLoopRun through
+// BrowserMainParts::PostDestroyThreads to occur, i.e. we pretend the
+// message loop finished, all threads are stopped in sequence and
+// PreStopThread/PostStopThread gets called, and at least,
+// PostDestroyThreads is called.
+//
+// As this violates the normal order of shutdown, likely leaving the
+// process in a bad state, the last thing this function does is
+// terminate the process (right after calling
+// BrowserMainParts::PostDestroyThreads).
+CONTENT_EXPORT void ImmediateShutdownAndExitProcess();
+
+}  // namespace content
+
+#endif  // CONTENT_PUBLIC_BROWSER_BROWSER_SHUTDOWN_H_