Implement ChildThread::shutdown and clear members that have refs into blink

content/child/child_thread.cc

 // Copyright (c) 2012 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 "content/child/child_thread.h"
 
 #include "base/allocator/allocator_extension.h"
 #include "base/base_switches.h"
 #include "base/command_line.h"
 #include "base/lazy_instance.h"
@@ skipping 177 matching lines @@
   // NOTE: this also has the side-effect of not closing the main IPC channel to
   // the browser process.  This is needed because this is the signal that the
   // browser uses to know that this process has died, so we need it to be alive
   // until this process is shut down, and the OS closes the handle
   // automatically.  We used to watch the object handle on Windows to do this,
   // but it wasn't possible to do so on POSIX.
   channel_->ClearIPCTaskRunner();
   g_lazy_tls.Pointer()->Set(NULL);
 }
 
+void ChildThread::Shutdown() {
+  // Delete objects that hold references to blink so derived classes can
+  // safely shutdown blink in their Shutdown implementation.
+  file_system_dispatcher_.reset();
+}
+
 void ChildThread::OnChannelConnected(int32 peer_pid) {
   channel_connected_factory_.InvalidateWeakPtrs();
 }
 
 void ChildThread::OnChannelError() {
   set_on_channel_error_called(true);
   base::MessageLoop::current()->Quit();
 }
 
 bool ChildThread::Send(IPC::Message* msg) {
@@ skipping 61 matching lines @@
 #endif
   return shared_buf.release();
 }
 
 bool ChildThread::OnMessageReceived(const IPC::Message& msg) {
   // Resource responses are sent to the resource dispatcher.
   if (resource_dispatcher_->OnMessageReceived(msg))
     return true;
   if (socket_stream_dispatcher_->OnMessageReceived(msg))
     return true;
-  if (file_system_dispatcher_->OnMessageReceived(msg))
+  if (file_system_dispatcher_ &&

[jam, 2013/07/23 16:44:23]

are you sure this can be called after shutdown?

+      file_system_dispatcher_->OnMessageReceived(msg))
     return true;
   if (quota_dispatcher_->OnMessageReceived(msg))
     return true;
 
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(ChildThread, msg)
     IPC_MESSAGE_HANDLER(ChildProcessMsg_Shutdown, OnShutdown)
 #if defined(IPC_MESSAGE_LOG_ENABLED)
     IPC_MESSAGE_HANDLER(ChildProcessMsg_SetIPCLoggingEnabled,
                         OnSetIPCLoggingEnabled)
@@ skipping 98 matching lines @@
   // inflight that would addref it.
   Send(new ChildProcessHostMsg_ShutdownRequest);
 }
 
 void ChildThread::EnsureConnected() {
   LOG(INFO) << "ChildThread::EnsureConnected()";
   base::KillProcess(base::GetCurrentProcessHandle(), 0, false);
 }
 
 }  // namespace content