This randomized, multicenter, double-blind, placebo-controlled study will evaluate the efficacy and safety of onartuzumab (MetMAb) in combination with Tarceva (erlotinib) in participants with incurable non-small cell lung cancer identified to be Met diagnostic-positive. Participants will be randomized to receive either onartuzumab (MetMAb) or placebo in combination with erlotinib. Anticipated time on study treatment is until disease progression or unacceptable toxicity occurs.