Check that all RenderProcessHost(s) are terminated.

content/browser/browser_main_loop.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/browser/browser_main_loop.h"
 
 #include <stddef.h>
 
 #include <string>
 #include <utility>
@@ skipping 1066 matching lines @@
         ResetThread_PROCESS_LAUNCHER(std::move(process_launcher_thread_));
         break;
       }
       case BrowserThread::CACHE: {
         TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:CacheThread");
         ResetThread_CACHE(std::move(cache_thread_));
         break;
       }
       case BrowserThread::IO: {
         TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:IOThread");
+        // IO thread is about to be destoyed.
+        // All IO-thread resources held by RenderProcessHost(s) must have been
+        // released by now, which happens when IPC channel to the renderer
+        // process is destoyed.
+        CHECK(!RenderProcessHostImpl::HasAnyConnection());

[alokp, 2016/07/08 17:30:15]

jam@: Is this a valid assumption?

We are hitting a CHECK in AudioManager destructor which verifies that no audio
output stream outlives AudioManager. The streams owned by RenderProcessHostImpl
are released when IPC channel is reset. From the crash reports it seems that we
have instances of RPHI with valid IPC channel.

We explicitly cleanup other child process during shutdown:
https://cs.chromium.org/chromium/src/content/browser/browser_process_sub_thre...

But I did not find anything for renderer processes. Should I expect all
instances of RPHI be destroyed or at least disconnected by now?

         ResetThread_IO(std::move(io_thread_));
         break;
       }
       case BrowserThread::UI:
       case BrowserThread::ID_COUNT:
       default:
         NOTREACHED();
         break;
     }
   }
@@ skipping 417 matching lines @@
     scoped_refptr<base::SingleThreadTaskRunner> worker_task_runner =
         audio_thread_->task_runner();
     audio_manager_ = media::AudioManager::Create(std::move(audio_task_runner),
                                                  std::move(worker_task_runner),
                                                  MediaInternals::GetInstance());
   }
   CHECK(audio_manager_);
 }
 
 }  // namespace content