[tools] Remove timestamp and print log levels at fixed width

Originally timestamps were added in crrev.com/c/1159361 to ease debugging. Since
then, however, timestamps were introduce to the LogDog viewer and are rendered
in a separate column, making it easier to scan text for important messages
starting with '>>>'. We do keep the log level, but make sure that it always
takes a fixed width such that the actual messages are aligned vertically.

R=machenbach@chromium.org

No-Try: true
Change-Id: I3a741069824aa25e674aca79da03a725017cb956
Reviewed-on: https://chromium-review.googlesource.com/c/1291370Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Sergiy Byelozyorov <sergiyb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56834}

tools/run_perf.py

@@ -964,11 +964,7 @@ def Main(args):
 
   (options, args) = parser.parse_args(args)
 
-  if options.buildbot:
-    logging.basicConfig(
-        level=logging.INFO, format="%(asctime)s %(levelname)s %(message)s")
-  else:
-    logging.basicConfig(level=logging.INFO, format="%(message)s")
+  logging.basicConfig(level=logging.INFO, format="%(levelname)-8s  %(message)s")
 
   if len(args) == 0:  # pragma: no cover
     parser.print_help()