Move back to alerting on the whole tile.
Move back to alerting on the whole tile.

The last change that ignored steps in the first or last 5 commits
seems to have fixed our noise issue. Now go back to building alerts
on the whole tile to we can compare results to using the /cluster
page.

BUG=skia:

Review URL: https://codereview.chromium.org/815733003

Tiger66639/skia-buildbot,google/skia-buildbot,google/skia-buildbot,Tiger66639/skia-buildbot,google/skia-buildbot,Tiger66639/skia-buildbot,google/skia-buildbot,Tiger66639/skia-buildbot,google/skia-buildbot,google/skia-buildbot,google/skia-buildbot,Tiger66639/skia-buildbot,google/skia-buildbot,Tiger66639/skia-buildbot,Tiger66639/skia-buildbot