By Sarah McBride SAN FRANCISCO (Reuters) – A Google Inc commuter bus was blocked in San Franciscos Mission district for about a half hour Monday morning, highlighting many residents growing concern that an influx of affluent technology workers is driving up costs in the city. San Francisco, not for sale and Stop evictions now numbered among the slogans yellow-vested protesters chanted as they surrounded the double-decker bus. Googles offices are in Mountain View, about 34 miles away from the incident. The protest, organized by an advocacy group called Heart of the City, took aim at private commuter buses which whisk thousands of employees from stops around San Francisco to jobs at technology companies south of the city such as Apple Inc, Facebook Inc and Google.