Child thread attachment broker should never be destroyed.

content/child/child_thread_impl.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_impl.h"
 
 #include <signal.h>
 #include <string>
 #include <utility>
 
@@ skipping 353 matching lines @@
   // We must make sure to instantiate the IPC Logger *before* we create the
   // channel, otherwise we can get a callback on the IO thread which creates
   // the logger, and the logger does not like being created on the IO thread.
   IPC::Logging::GetInstance();
 #endif
 
 #if USE_ATTACHMENT_BROKER
   // The only reason a global would already exist is if the thread is being run
   // in the browser process because of a command line switch.
   if (!IPC::AttachmentBroker::GetGlobal()) {
-    attachment_broker_.reset(
-        IPC::AttachmentBrokerUnprivileged::CreateBroker().release());
+    // Intentionally leak the attachment broker so that it is never destroyed.

[Avi (use Gerrit), 2016/02/06 07:03:40]

Mention _why_ you leak it, not just that you do.

+    attachment_broker_ =
+        IPC::AttachmentBrokerUnprivileged::CreateBroker().release();
   }
 #endif
 
   channel_ =
       IPC::SyncChannel::Create(this, ChildProcess::current()->io_task_runner(),
                                ChildProcess::current()->GetShutDownEvent());
 #ifdef IPC_MESSAGE_LOG_ENABLED
   if (!IsInBrowserProcess())
     IPC::Logging::GetInstance()->SetIPCSender(this);
 #endif
@@ skipping 346 matching lines @@
 void ChildThreadImpl::EnsureConnected() {
   VLOG(0) << "ChildThreadImpl::EnsureConnected()";
   base::Process::Current().Terminate(0, false);
 }
 
 bool ChildThreadImpl::IsInBrowserProcess() const {
   return browser_process_io_runner_;
 }
 
 }  // namespace content