Revert 289542 "Disable leaky NotificationToNotificationOptions"

The leak is in the actual code, not just in the test.

> Disable leaky NotificationToNotificationOptions
> 
> LSan detected a memory leak in this newly added test.
> 
> BUG=403759
> TEST=Disabling leaky test
> TBR=liyanhou
> 
> Review URL: https://codereview.chromium.org/470153002

TBR=bartfab@chromium.org

Review URL: https://codereview.chromium.org/470113003

Cr-Commit-Position: refs/heads/master@{#289543}
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@289543 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/notifications/notification_conversion_helper_unittest.cc

@@ -77,10 +77,7 @@ class NotificationConversionHelperTest : public testing::Test {
   DISALLOW_COPY_AND_ASSIGN(NotificationConversionHelperTest);
 };
 
-// TODO(liyanhou): This test is disabled due to memory leaks. Fix and re-enable.
-// http://crbug.com/403759
-TEST_F(NotificationConversionHelperTest,
-       DISABLED_NotificationToNotificationOptions) {
+TEST_F(NotificationConversionHelperTest, NotificationToNotificationOptions) {
   // Create a notification of image type
   scoped_ptr<Notification> notification1 =
       CreateNotification(message_center::NOTIFICATION_TYPE_IMAGE);