The code assumed an else-if would end in an else. We can also save a
few allocations in the cases where there is no else.

BUG=angle:699

Change-Id: I550857366775b4a34aea97e117ef732297d3f448
Reviewed-on: https://chromium-review.googlesource.com/208681Tested-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Nicolas Capens <capn@chromium.org>