[renderer]: Fix RendererScheduler shutdown logic to ensure it is shutdown before the MessageLoop.

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 184bcc6121ffa5f80987507691e0facbb2ac4b44..8f4bf998ba35f3c0e1f4ef2270692e3c4b802ed6 100644
--- a/content/renderer/render_thread_impl.cc
+++ b/content/renderer/render_thread_impl.cc
@@ -757,11 +757,12 @@ void RenderThreadImpl::Shutdown() {
   NPChannelBase::CleanupChannels();
 #endif
 
-  // Shut down the message loop before shutting down Blink.
-  // This prevents a scenario where a pending task in the message loop accesses
-  // Blink objects after Blink shuts down.
+  // Shut down the message loop and the renderer scheduler before shutting down
+  // Blink. This prevents a scenario where a pending task in the message loop
+  // accesses Blink objects after Blink shuts down.
   // This must be at the very end of the shutdown sequence. You must not touch
   // the message loop after this.
+  renderer_scheduler_->Shutdown();
   main_message_loop_.reset();
   if (blink_platform_impl_)
     blink::shutdown();