TripAdvisor Inc.’s shares fell after Google Inc. agreed to buy all of John Wiley & Sons Inc.’s travel assets, including the Frommer’s brand, as the owner of the world’s largest Internet search engine expands local services. The deal would give Google about 350 travel guides and the Frommers.com travel-planning website. Google is providing more of its own content to Web surfers in a bid to attract users and advertisers from sites such as Yelp Inc. and Newton-based TripAdvisor.