Avoid shutdown crash if audio thread is hung.

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 1335 matching lines @@
   {
     TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:GamepadService");
     device::GamepadService::GetInstance()->Terminate();
   }
   {
     TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:DeleteDataSources");
     URLDataManager::DeleteDataSources();
   }
   {
     TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:AudioMan");
-    audio_manager_->Shutdown();
+    if (!audio_manager_->Shutdown()) {
+      // Intentionally leak AudioManager if shutdown failed.
+      // We might run into various CHECK(s) in AudioManager destructor.
+      ignore_result(audio_manager_.release());
+    }
   }
 
   if (parts_) {
     TRACE_EVENT0("shutdown", "BrowserMainLoop::Subsystem:PostDestroyThreads");
     parts_->PostDestroyThreads();
   }
 }
 
 #if !defined(OS_ANDROID)
 cc::SurfaceManager* BrowserMainLoop::GetSurfaceManager() const {
@@ skipping 416 matching lines @@
         base::MakeUnique<media::AudioThreadImpl>(),
         MediaInternals::GetInstance());
   }
   CHECK(audio_manager_);
 
   audio_system_ = media::AudioSystemImpl::Create(audio_manager_.get());
   CHECK(audio_system_);
 }
 
 }  // namespace content