Have mash_browser_tests recreate BackgroundServiceManager per test

ui/views/mus/aura_init.cc

Index: ui/views/mus/aura_init.cc
diff --git a/ui/views/mus/aura_init.cc b/ui/views/mus/aura_init.cc
index 7f73dc190f410c7ca759ac28be41f692f7b3c29e..e3fc9ea45694e9714e206a54e394cb71307a4a21 100644
--- a/ui/views/mus/aura_init.cc
+++ b/ui/views/mus/aura_init.cc
@@ -110,7 +110,11 @@ void AuraInit::InitializeResources(service_manager::Connector* connector) {
   catalog::ResourceLoader loader;
   filesystem::mojom::DirectoryPtr directory;
   connector->BindInterface(catalog::mojom::kServiceName, &directory);
-  CHECK(loader.OpenFiles(std::move(directory), resource_paths));
+  if (!loader.OpenFiles(std::move(directory), resource_paths)) {

[sky, 2017/05/12 17:16:47]

Same comment here.

+    LOG(ERROR) << "AuraInit failed to open resource files.\n";
+    return;
+  }
+
   ui::RegisterPathProvider();
   base::File pak_file = loader.TakeFile(resource_file_);
   base::File pak_file_2 = pak_file.Duplicate();