Cleanup & tests for the mac startup pref migration.

chrome/browser/prefs/session_startup_pref_unittest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/prefs/session_startup_pref.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/test/base/testing_pref_service.h"
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ skipping 141 matching lines @@
   // using the pref service directly.
   pref_service_->SetInteger(prefs::kRestoreOnStartup, /*kPrefValueHomePage*/ 0);
   pref_service_->SetString(prefs::kHomePage, "http://chromium.org/");
   pref_service_->SetBoolean(prefs::kHomePageIsNewTabPage, true);
 
   SessionStartupPref pref = SessionStartupPref::GetStartupPref(
       pref_service_.get());
 
   EXPECT_EQ(SessionStartupPref::DEFAULT, pref.type);
 }
+
+#if defined(OS_MACOSX)
+// See SessionStartupPref::MigrateMacDefaultPrefIfNecessary.
+TEST_F(SessionStartupPrefTest, MacDefaultStartupPrefMigration) {
+  if (!restore_utils::IsWindowRestoreEnabled())
+    return;
+
+  // Use an old profile.
+  pref_service_->SetString(prefs::kProfileCreatedByVersion, "19.0.0.0");
+  ASSERT_TRUE(SessionStartupPref::TypeIsDefault(pref_service_.get()));
+
+  // Trigger the migration.
+  SessionStartupPref pref = SessionStartupPref::GetStartupPref(
+      pref_service_.get());
+
+  // The pref is now explicit.
+  EXPECT_EQ(SessionStartupPref::LAST, pref.type);
+  EXPECT_FALSE(SessionStartupPref::TypeIsDefault(pref_service_.get()));
+}
+#endif