Mark supervised profiles as such immediately when they're created.

chrome/test/base/testing_profile.cc

Index: chrome/test/base/testing_profile.cc
diff --git a/chrome/test/base/testing_profile.cc b/chrome/test/base/testing_profile.cc
index f928f39da3773ebd85521f3542230383fb445221..c2a40a93fe7788b067d938bcb7adf0662e4b643a 100644
--- a/chrome/test/base/testing_profile.cc
+++ b/chrome/test/base/testing_profile.cc
@@ -230,6 +230,7 @@ TestingProfile::TestingProfile(
     scoped_refptr<ExtensionSpecialStoragePolicy> extension_policy,
     scoped_ptr<PrefServiceSyncable> prefs,
     bool incognito,
+    const std::string& managed_user_id,
     const TestingFactories& factories)
     : start_time_(Time::Now()),
       prefs_(prefs.release()),
@@ -237,6 +238,7 @@ TestingProfile::TestingProfile(
       incognito_(incognito),
       force_incognito_(false),
       original_profile_(NULL),
+      managed_user_id_(managed_user_id),
       last_session_exited_cleanly_(true),
       extension_special_storage_policy_(extension_policy),
       profile_path_(path),
@@ -353,8 +355,10 @@ void TestingProfile::FinishInit() {
       content::Source<Profile>(static_cast<Profile*>(this)),
       content::NotificationService::NoDetails());
 
-  if (delegate_)
+  if (delegate_) {
+    delegate_->OnPrefsLoaded(this);
     delegate_->OnProfileCreated(this, true, false);
+  }
 }
 
 TestingProfile::~TestingProfile() {
@@ -584,7 +588,7 @@ Profile* TestingProfile::GetOriginalProfile() {
 }
 
 bool TestingProfile::IsManaged() {
-  return !GetPrefs()->GetString(prefs::kManagedUserId).empty();
+  return !managed_user_id_.empty();
 }
 
 ExtensionService* TestingProfile::GetExtensionService() {
@@ -857,6 +861,11 @@ void TestingProfile::Builder::SetIncognito() {
   incognito_ = true;
 }
 
+void TestingProfile::Builder::SetManagedUserId(
+    const std::string& managed_user_id) {
+  managed_user_id_ = managed_user_id_;
+}
+
 void TestingProfile::Builder::AddTestingFactory(
     BrowserContextKeyedServiceFactory* service_factory,
     BrowserContextKeyedServiceFactory::FactoryFunction callback) {
@@ -866,11 +875,13 @@ void TestingProfile::Builder::AddTestingFactory(
 scoped_ptr<TestingProfile> TestingProfile::Builder::Build() {
   DCHECK(!build_called_);
   build_called_ = true;
+
   return scoped_ptr<TestingProfile>(new TestingProfile(
       path_,
       delegate_,
       extension_policy_,
       pref_service_.Pass(),
       incognito_,
+      managed_user_id_,
       testing_factories_));
 }