wireprotov2server: use our JSON encoder

wireprotov2server: use our JSON encoder

Python's json module doesn't like to encode bytes instances.
This makes this code difficult to work with Python 3.

We simply swap in Mercurial's JSON encoder to work around it.

Differential Revision: https://phab.mercurial-scm.org/D5712

--- a/mercurial/wireprotov2server.py	Fri Jan 25 17:11:49 2019 -0800
+++ b/mercurial/wireprotov2server.py	Sat Jan 26 10:00:17 2019 -0800
@@ -23,6 +23,7 @@
     narrowspec,
     pycompat,
     streamclone,
+    templatefilters,
     util,
     wireprotoframing,
     wireprototypes,
@@ -148,8 +149,6 @@
     tracker. We then dump the log of all that activity back out to the
     client.
     """
-    import json
-
     # Reflection APIs have a history of being abused, accidentally disclosing
     # sensitive data, etc. So we have a config knob.
     if not ui.configbool('experimental', 'web.api.debugreflect'):
@@ -175,12 +174,11 @@
                                                   frame.payload))
 
         action, meta = reactor.onframerecv(frame)
-        states.append(json.dumps((action, meta), sort_keys=True,
-                                 separators=(', ', ': ')))
+        states.append(templatefilters.json((action, meta)))
 
     action, meta = reactor.oninputeof()
     meta['action'] = action
-    states.append(json.dumps(meta, sort_keys=True, separators=(', ',': ')))
+    states.append(templatefilters.json(meta))
 
     res.status = b'200 OK'
     res.headers[b'Content-Type'] = b'text/plain'