Remove the code to wait on disconnected child processes to get the exit code. This was done in r101…

content/common/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/common/child_thread.h"
 
 #include "base/allocator/allocator_extension.h"
 #include "base/command_line.h"
 #include "base/message_loop.h"
 #include "base/process.h"
@@ skipping 53 matching lines @@
   channel_->AddFilter(new ChildTraceMessageFilter());
 }
 
 ChildThread::~ChildThread() {
 #ifdef IPC_MESSAGE_LOG_ENABLED
   IPC::Logging::GetInstance()->SetIPCSender(NULL);
 #endif
 
   channel_->RemoveFilter(sync_message_filter_.get());
 
-  // Close this channel before resetting the message loop attached to it so
-  // the message loop can call ChannelProxy::Context::OnChannelClosed(), which
-  // releases the reference count to this channel.
-  channel_->Close();
-
   // The ChannelProxy object caches a pointer to the IPC thread, so need to
   // reset it as it's not guaranteed to outlive this object.
   // 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();
 }
@@ skipping 188 matching lines @@
   }
 
   // The child process shutdown sequence is a request response based mechanism,
   // where we send out an initial feeler request to the child process host
   // instance in the browser to verify if it's ok to shutdown the child process.
   // The browser then sends back a response if it's ok to shutdown. This avoids
   // race conditions if the process refcount is 0 but there's an IPC message
   // inflight that would addref it.
   Send(new ChildProcessHostMsg_ShutdownRequest);
 }