Mostly cosmetic changes. The biggest change is to encode block result
types using symbolic names instead of hex numbers.

R=ahaas@chromium.org

Change-Id: Ic0e6eccf687338e68508094168ddd70734cef301
Reviewed-on: https://chromium-review.googlesource.com/973527
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#52138}