SAN FRANCISCO — Google unveiled a beta version of its Chrome OS and an early test version of its branded netbook Tuesday morning, a big bet by the search giant to help drive computing to the cloud — and to the popular web-based services that are its bread and butter.

Google’s release of the new OS, related but separate to its mobile OS Android, comes after a year of development and at a time when cloud computing — and the simpler machines that access applications on distant servers rather than running them on a hard drive — seems to have passed a sort of tipping point of respectability. It’s no coincidence, surely, that Microsoft is touting its own cloud-based approach in a huge