Samsung didn't do anything about Google buying Motorola. And that was at a time I'd argue Samsung was much less dominant in the market than it is now. They don't have a whole lot to worry about.
I may be out of date, but I hated the last samsung phone I had because they did not realize this and subjected their users to touchwhizz.
The also need to improve at supporting their software and keeping android up to date.
Google deciding to change something is one of Samsung's biggest corporate risks since they're so dependent on them with the phone business.