Handful of changes to get mus to shutdown correctly

components/mus/mus_app.cc

Index: components/mus/mus_app.cc
diff --git a/components/mus/mus_app.cc b/components/mus/mus_app.cc
index 9f226a9f8d99c6d5bab5380c98f1c6e4a66ac995..8128d020a583e233917c31c7935c55129cddfefc 100644
--- a/components/mus/mus_app.cc
+++ b/components/mus/mus_app.cc
@@ -69,10 +69,13 @@ struct MandolineUIServicesApp::UserState {
 MandolineUIServicesApp::MandolineUIServicesApp() {}
 
 MandolineUIServicesApp::~MandolineUIServicesApp() {
-  if (platform_display_init_params_.gpu_state)
-    platform_display_init_params_.gpu_state->StopThreads();
   // Destroy |window_server_| first, since it depends on |event_source_|.
+  // WindowServer (or more correctly its Displays) may have state that needs to
+  // be destroyed before GpuState as well.
   window_server_.reset();
+
+  if (platform_display_init_params_.gpu_state)
+    platform_display_init_params_.gpu_state->StopThreads();
 }
 
 void MandolineUIServicesApp::InitializeResources(mojo::Connector* connector) {
@@ -181,7 +184,9 @@ void MandolineUIServicesApp::OnFirstDisplayReady() {
 }
 
 void MandolineUIServicesApp::OnNoMoreDisplays() {
-  base::MessageLoop::current()->QuitWhenIdle();
+  // We may get here from the destructor, in which case there is no messageloop.
+  if (base::MessageLoop::current())
+    base::MessageLoop::current()->QuitWhenIdle();
 }
 
 scoped_ptr<ws::WindowTreeBinding>