Re-fix http://crbug.com/87176, and add a test.

content/browser/renderer_host/render_process_host_impl.cc

Index: content/browser/renderer_host/render_process_host_impl.cc
diff --git a/content/browser/renderer_host/render_process_host_impl.cc b/content/browser/renderer_host/render_process_host_impl.cc
index 21c20c9fa3cb30f9d94e39ee60cda8f577ca6f4b..fae674d564cf5ac8b0a63425999bc4faafa9f45d 100644
--- a/content/browser/renderer_host/render_process_host_impl.cc
+++ b/content/browser/renderer_host/render_process_host_impl.cc
@@ -387,6 +387,7 @@ RenderProcessHostImpl::RenderProcessHostImpl(
               FROM_HERE, base::TimeDelta::FromSeconds(5),
               this, &RenderProcessHostImpl::ClearTransportDIBCache),
           is_initialized_(false),
+          child_process_launcher_factory_(base::Bind(&NewChildProcessLauncher)),
           id_(ChildProcessHostImpl::GenerateChildProcessUniqueId()),
           browser_context_(browser_context),
           storage_partition_impl_(storage_partition_impl),
@@ -539,7 +540,7 @@ bool RenderProcessHostImpl::Init() {
     // Spawn the child process asynchronously to avoid blocking the UI thread.
     // As long as there's no renderer prefix, we can use the zygote process
     // at this stage.
-    child_process_launcher_.reset(new ChildProcessLauncher(
+    child_process_launcher_ = child_process_launcher_factory_.Run(
 #if defined(OS_WIN)
         new RendererSandboxedProcessLauncherDelegate,
 #elif defined(OS_POSIX)
@@ -549,7 +550,7 @@ bool RenderProcessHostImpl::Init() {
 #endif
         cmd_line,
         GetID(),
-        this));
+        this);
 
     fast_shutdown_started_ = false;
   }
@@ -603,11 +604,13 @@ void RenderProcessHostImpl::CreateMessageFilters() {
   media::AudioManager* audio_manager = BrowserMainLoop::GetAudioManager();
   MediaStreamManager* media_stream_manager =
       BrowserMainLoop::GetMediaStreamManager();
-  channel_->AddFilter(new AudioInputRendererHost(audio_manager,
-                                                 media_stream_manager));
-  channel_->AddFilter(new AudioRendererHost(
-      GetID(), audio_manager, BrowserMainLoop::GetAudioMirroringManager(),
-      media_internals, media_stream_manager));
+  if (audio_manager && media_stream_manager) {
+    channel_->AddFilter(new AudioInputRendererHost(audio_manager,
+                                                   media_stream_manager));
+    channel_->AddFilter(new AudioRendererHost(
+        GetID(), audio_manager, BrowserMainLoop::GetAudioMirroringManager(),
+        media_internals, media_stream_manager));
+  }
   channel_->AddFilter(new VideoCaptureHost());
   channel_->AddFilter(new AppCacheDispatcherHost(
       storage_partition_impl_->GetAppCacheService(),
@@ -1683,11 +1686,11 @@ void RenderProcessHostImpl::EndFrameSubscription(int route_id) {
 }
 
 void RenderProcessHostImpl::OnShutdownRequest() {
-  // Don't shut down if there are more active RenderViews than the one asking
-  // to close, or if there are pending RenderViews being swapped back in.
+  // Don't shut down if there are active RenderViews, or if there are pending
+  // RenderViews being swapped back in.
   // In single process mode, we never shutdown the renderer.
   int num_active_views = GetActiveViewCount();
-  if (pending_views_ || num_active_views > 1 || run_renderer_in_process())
+  if (pending_views_ || num_active_views > 0 || run_renderer_in_process())
     return;
 
   // Notify any contents that might have swapped out renderers from this