chore(3p): gerrit: 3.4.0 -> 3.6.1

This change cannot be deployed OOTB: you must upgrade
by 3.5.2+ first, and run copy-approvals.

Change-Id: Ia2e49da4d801a21a3db59e2d5b054eeb46d7dc79
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6505
Tested-by: BuildkiteCI
Reviewed-by: tazjin <tazjin@tvl.su>

third_party/gerrit/0001-Syntax-highlight-nix.patch

@@ -0,0 +1,37 @@
+From fea4416001e5dd097d70166778fa55c6b20fae39 Mon Sep 17 00:00:00 2001
+From: Luke Granger-Brown <git@lukegb.com>
+Date: Thu, 2 Jul 2020 23:02:32 +0100
+Subject: [PATCH 1/3] Syntax highlight nix
+
+---
+ .../app/embed/diff/gr-syntax-layer/gr-syntax-layer-worker.ts     | 1 +
+ resources/com/google/gerrit/server/mime/mime-types.properties    | 1 +
+ 2 files changed, 2 insertions(+)
+
+diff --git a/polygerrit-ui/app/embed/diff/gr-syntax-layer/gr-syntax-layer-worker.ts b/polygerrit-ui/app/embed/diff/gr-syntax-layer/gr-syntax-layer-worker.ts
+index 9938d3408d..f6f634ad31 100644
+--- a/polygerrit-ui/app/embed/diff/gr-syntax-layer/gr-syntax-layer-worker.ts
++++ b/polygerrit-ui/app/embed/diff/gr-syntax-layer/gr-syntax-layer-worker.ts
+@@ -93,6 +93,7 @@ const LANGUAGE_MAP = new Map<string, string>([
+   ['text/x-vhdl', 'vhdl'],
+   ['text/x-yaml', 'yaml'],
+   ['text/vbscript', 'vbscript'],
++  ['text/x-nix', 'nix'],
+ ]);
+ 
+ const CLASS_PREFIX = 'gr-diff gr-syntax gr-syntax-';
+diff --git a/resources/com/google/gerrit/server/mime/mime-types.properties b/resources/com/google/gerrit/server/mime/mime-types.properties
+index 5a08e66067..c0c092c712 100644
+--- a/resources/com/google/gerrit/server/mime/mime-types.properties
++++ b/resources/com/google/gerrit/server/mime/mime-types.properties
+@@ -149,6 +149,7 @@ mscin = text/x-mscgen
+ msgenny = text/x-msgenny
+ nb = text/x-mathematica
+ nginx.conf = text/x-nginx-conf
++nix = text/x-nix
+ nsh = text/x-nsis
+ nsi = text/x-nsis
+ nt = text/n-triples
+-- 
+2.36.0
+