Change filtering of messages in experimental ChangeLog

Example:
All entries: https://imgur.com/a/2jhhwRc
New default view: https://imgur.com/a/GCbKVll
Old default view: https://imgur.com/a/vdRuv2c

Bug: Issue 11774, Issue 8164
Change-Id: I74b36f956fc44bc24d48c7eea1bb2eac7b6b1a86
diff --git a/polygerrit-ui/app/constants/constants.js b/polygerrit-ui/app/constants/constants.js
index cab50f6..36e0b86 100644
--- a/polygerrit-ui/app/constants/constants.js
+++ b/polygerrit-ui/app/constants/constants.js
@@ -33,3 +33,13 @@
   COMMENT_THREADS: '_commentThreads',
 };
 
+/**
+ * @enum
+ * @desc Tag names of change log messages.
+ */
+export const MessageTags = {
+  TAG_DELETE_REVIEWER: 'autogenerated:gerrit:deleteReviewer',
+  TAG_NEW_PATCHSET: 'autogenerated:gerrit:newPatchSet',
+  TAG_NEW_WIP_PATCHSET: 'autogenerated:gerrit:newWipPatchSet',
+  TAG_REVIEWER_UPDATE: 'autogenerated:gerrit:reviewerUpdate',
+};