[cros] Fake a stub user login when no --login-manager and --login-user are given.

chrome/browser/profiles/profile_manager.cc

Index: chrome/browser/profiles/profile_manager.cc
diff --git a/chrome/browser/profiles/profile_manager.cc b/chrome/browser/profiles/profile_manager.cc
index 7855e32ac46e39eea8f774893fab678ddb8bd90c..211f89c1ae81e994a4d3ab7541d8fdcf1e73d8ed 100644
--- a/chrome/browser/profiles/profile_manager.cc
+++ b/chrome/browser/profiles/profile_manager.cc
@@ -164,6 +164,13 @@ void OnOpenWindowForNewProfile(Profile* profile,
 
 } // namespace
 
+// static
+#if defined(OS_CHROMEOS)
+const char ProfileManager::kTestUserProfile[] = "test-user";
+#else
+const char ProfileManager::kTestUserProfile[] = "Default";
+#endif
+
 #if defined(ENABLE_SESSION_SERVICE)
 // static
 void ProfileManager::ShutdownSessionServices() {