Microsoft has announced the shuttering of its video game streaming service Mixer, bought to challenge Amazon’s Twitch and as a hedge against Google’s YouTube Gaming. With Microsoft backing, including the influential Xbox platform and its upcoming next-gen console, Mixer could have made a go of it – but evidently, Microsoft has read the tea leaves. Based on research for the upcoming forecast from our research arm Rethink TV on video consumption in the non-pay TV realm, Mixer was circling the drain already. It was never more than 2.5% of active viewers, according to our measurements, and seemed to have already lost ground to Facebook Gaming and YouTube Gaming. In our counting system, Twitch’s lowest active-viewer share was 36.3%, but its…