Better handle SK_ABORT.

The Chromium logging of SkDebugf messages was originally intended to be
INFO, but was sometimes changed to ERROR because otherwise the SkDebugf
in SK_ABORT was not logged, making crashes more difficult to diagnose.
This was done with https://crrev.com/c/1348630 but this leads to all
SkDebugf calls being logged as ERROR when DCHECK_IS_ON.

Instead, restore SkDebugf messages to INFO and define SK_ABORT directly
and define it to work the way it is expected to work, as a FATAL message
which aborts.

Bug: chromium:1050863
Change-Id: If4c5525cd3f0ee762ed9a95c22148970e6962dd5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2316816


Commit-Queue: Ben Wagner <bungeman@chromium.org>
Reviewed-by: Brian Salomon <bsalomon@google.com>
Cr-Commit-Position: refs/heads/master@{#791460}