Show comments on diff dropdown

Since the diff view now has access to the same comment structure as the
change view/file list header via the comment api, patchsets can now
display comment counts in the dropdown.

Bug: Issue 7212
Change-Id: I85697c770862de48b2b2ce82649f1b8873ab9480
diff --git a/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view.html b/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view.html
index a080396..91d3a3e 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view.html
+++ b/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view.html
@@ -286,6 +286,7 @@
           <gr-patch-range-select
               id="rangeSelect"
               change-num="[[_changeNum]]"
+              comments="[[_changeComments.comments]]"
               patch-num="[[_patchRange.patchNum]]"
               base-patch-num="[[_patchRange.basePatchNum]]"
               files-weblinks="[[_filesWeblinks]]"
diff --git a/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view.js b/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view.js
index 6f25c55..7c46b58 100644
--- a/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view.js
+++ b/polygerrit-ui/app/elements/diff/gr-diff-view/gr-diff-view.js
@@ -71,6 +71,7 @@
        * }}
        */
       _change: Object,
+      /** @type {?} */
       _changeComments: Object,
       _changeNum: String,
       _diff: Object,