metrics: treat slash '/' as metric delimiter

Summary:
Slash is probably the standard metric delimiter nowadays. Since we don't have
that many metrics I think that it makes sense to look at slash as the
standard metric delimiter going forward.
This diff updates parsing of metric names to treat both '_' and '/' as
delimiters.

Reviewed By: quark-zju

Differential Revision: D23577876

fbshipit-source-id: 03997b1285df9c52d6e2837b5af5372deb69b133

eden/scm/edenscm/mercurial/dispatch.py

@@ -425,9 +425,10 @@ def dispatch(req):
             # Re-arrange metrics so "a_b_c", "a_b_d", "a_c" becomes
             # {'a': {'b': {'c': ..., 'd': ...}, 'c': ...}
             metrics = {}
+            splitre = re.compile("_|/")
             for key, value in ui.metrics.stats.items():
                 cur = metrics
-                names = key.split("_")
+                names = splitre.split(key)
                 for name in names[:-1]:
                     cur = cur.setdefault(name, {})
                 cur[names[-1]] = value