[PATCH 5 of 5 V3] perf: disable revlogs clearing in `perftags` by default

[Boris Feld]

# HG changeset patch
# User Boris Feld <boris.feld at octobus.net>
# Date 1542735864 0
#      Tue Nov 20 17:44:24 2018 +0000
# Node ID 400476885997b972298b537b5d694ba9500f3f90
# Parent  4394597460a13bcd6fc2b4d88826f9399ac27de0
# EXP-Topic perf-tags
# Available At https://bitbucket.org/octobus/mercurial-devel/
#              hg pull https://bitbucket.org/octobus/mercurial-devel/ -r 400476885997
perf: disable revlogs clearing in `perftags` by default

This aligns things with what `perfbookmarks` does. I decided to disable the
revlogs clearing by default to focus on the core logic by default, ignoring
side effects.

If we prefer to emphasize the side effect, we can instead keep this on in
`perftags` and enable it by default in `perfbookmarks`.

diff --git a/contrib/perf.py b/contrib/perf.py
--- a/contrib/perf.py
+++ b/contrib/perf.py
@@ -538,7 +538,7 @@ def perfheads(ui, repo, **opts):
 
 @command(b'perftags', formatteropts+
         [
-            (b'', b'clear-revlogs', True, 'refresh changelog and manifest'),
+            (b'', b'clear-revlogs', False, 'refresh changelog and manifest'),
         ])
 def perftags(ui, repo, **opts):
     import mercurial.changelog