emacs: Comment Gerrit URL bugfix.

Previously the host was hardcoded as
"chromium-review.googlesource.com" when generating links to the webUI
comments. This has now been remedied.

BUG=chromium:1111775
TEST=Tested links generated by gerrit-comments sections ui.

Change-Id: I686a40082885f55fc86ddc164e120c322cd14fb3
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/dev-util/+/2331865
Reviewed-by: Sean McAllister <smcallis@google.com>
Tested-by: Aaron Massey <aaronmassey@chromium.org>
Commit-Queue: Aaron Massey <aaronmassey@chromium.org>
diff --git a/contrib/emacs/gerrit-section.el b/contrib/emacs/gerrit-section.el
index 779436c..dc3d6ed 100644
--- a/contrib/emacs/gerrit-section.el
+++ b/contrib/emacs/gerrit-section.el
@@ -216,7 +216,8 @@
              ;; TODO buttonize link.
              (propertize
               (format
-               "https://chromium-review.googlesource.com/c/%s/+/%s/%s/%s#%s"
+               "https://%s/c/%s/+/%s/%s/%s#%s"
+               (gethash (gethash "change_id" change) gerrit--change-to-host)
                (url-hexify-string (gethash "project" change))
                (gethash "_number" change)
                ;; Default is nil if comments only on a single patch.
diff --git a/contrib/emacs/gerrit.el b/contrib/emacs/gerrit.el
index a810946..322f5c1 100644
--- a/contrib/emacs/gerrit.el
+++ b/contrib/emacs/gerrit.el
@@ -40,6 +40,12 @@
 Default is repo_root_path/.repo/manifests/default.xml")
 
 
+(defvar gerrit--change-to-host
+  (make-hash-table :test 'equal)
+  "Map showing => host.
+Needed for generating links.")
+
+
 (defun gerrit-init ()
   "Initialize Repo Gerrit state."
   (unless gerrit-repo-manifest
@@ -117,6 +123,9 @@
 Only fetches recent changes for open CLs."
   (let ((out-map (make-hash-table :test 'equal)))
     (loop for change across (gerrit--fetch-recent-changes host) do
+          (setf (gethash (gethash "change_id" change)
+                         gerrit--change-to-host)
+                host)
           (setf (gethash change out-map)
                 (gerrit--fetch-comments host change)))
     out-map))