Independent bookstores were battered first by discount chains like Barnes & Noble, then by super-efficient web retailers like Amazon.com. Now the electronic book age is dawning. With this latest challenge, these stores will soon have a new ally: the search giant Google, The New York Times reports. Later this summer, Google plans to introduce its long-awaited push into electronic books, called Google Editions. The company has revealed little about the venture thus far, describing it generally as an effort to sell digital books that will be readable within a Web browser and accessible from any internet-connected computing device. Now one element of Google Editions is coming into sharper focus. Google is on the verge of completing a deal with the American Booksellers Association, the trade group for independent bookstores, to make Google Editions the primary source of e-books on the web sites of hundreds of independent booksellers around the country, according to representatives of Google and the association.