When using Chrome, "Samsung Mobile Bookmarks" would always be the default and it is full of crap and it can't be deleted or altered. More bloat shoved down our throats. Anyway, I think I found the solution to removing it and I haven't had any issues yet. Go to Settings>More>Application Manager>All and disable com.android.providers.partnerbookmarks. Then restart the phone and those annoying bookmarks will go away.