Fixes for handling of MockDBusThreadManager::GetSystemBus().

chrome/browser/chromeos/dbus/cros_dbus_service.cc

Index: chrome/browser/chromeos/dbus/cros_dbus_service.cc
diff --git a/chrome/browser/chromeos/dbus/cros_dbus_service.cc b/chrome/browser/chromeos/dbus/cros_dbus_service.cc
index 7f821e3ed1649029672077346f4a6032cd997820..b9a4d83f20af883135e749f7610cc9ccb6046383 100644
--- a/chrome/browser/chromeos/dbus/cros_dbus_service.cc
+++ b/chrome/browser/chromeos/dbus/cros_dbus_service.cc
@@ -105,8 +105,8 @@ void CrosDBusService::Initialize() {
     LOG(WARNING) << "CrosDBusService was already initialized";
     return;
   }
-  if (base::chromeos::IsRunningOnChromeOS()) {
-    dbus::Bus* bus = DBusThreadManager::Get()->GetSystemBus();
+  dbus::Bus* bus = DBusThreadManager::Get()->GetSystemBus();
+  if (base::chromeos::IsRunningOnChromeOS() && bus) {
     CrosDBusServiceImpl* service = new CrosDBusServiceImpl(bus);
     service->RegisterServiceProvider(ProxyResolutionServiceProvider::Create());
     g_cros_dbus_service = service;