pulld: Can't do arithmetic on boolean metrics, so switch to Int64.
pulld: Can't do arithmetic on boolean metrics, so switch to Int64.

BUG=skia:

Review-Url: https://codereview.chromium.org/1949713002

google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot