  We explore the predictions for detectable gravitational-wave signals from
merging binary black holes formed through chemically homogeneous evolution in
massive short-period stellar binaries. We find that $\sim 500$ events per year
could be detected with advanced ground-based detectors operating at full
sensitivity. We analyze the distribution of detectable events, and conclude
that there is a very strong preference for detecting events with nearly equal
components (mass ratio $>0.66$ at 90\% confidence in our default model) and
high masses (total source-frame mass between $57$ and $103\, M_\odot$ at 90\%
confidence). We consider multiple alternative variations to analyze the
sensitivity to uncertainties in the evolutionary physics and cosmological
parameters, and conclude that while the rates are sensitive to assumed
variations, the mass distributions are robust predictions. Finally, we consider
the recently reported results of the analysis of the first 16 double-coincident
days of the O1 LIGO (Laser Interferometer Gravitational-wave Observatory)
observing run, and find that this formation channel is fully consistent with
the inferred parameters of the GW150914 binary black hole detection and the
inferred merger rate.
