Shutdown PeerConnectionDependencyFactory before Blink shutdown

content/renderer/render_thread_impl.cc

Index: content/renderer/render_thread_impl.cc
diff --git a/content/renderer/render_thread_impl.cc b/content/renderer/render_thread_impl.cc
index 0ca11970bf6422921335b358ec0ea8bed7144d77..981022c510cb7815e4f270993ca994f8cdc5955b 100644
--- a/content/renderer/render_thread_impl.cc
+++ b/content/renderer/render_thread_impl.cc
@@ -895,11 +895,8 @@ void RenderThreadImpl::Shutdown() {
 
 #if defined(ENABLE_WEBRTC)
   RTCPeerConnectionHandler::DestructAllHandlers();
-  // |peer_connection_factory_| cannot be deleted until after the main message
-  // loop has been destroyed.  This is because there may be pending tasks that
-  // hold on to objects produced by the PC factory that depend on threads owned
-  // by the PC factory.  Once those tasks have been freed, the factory can be
-  // deleted.
+  peer_connection_factory_->ShutDown();
+  peer_connection_factory_ = nullptr;
 #endif
   RemoveFilter(vc_manager_->video_capture_message_filter());
   vc_manager_.reset();