Handle unauthenticated users in when computing change list highlight In I93e61f4c98, the `_computeItemHighlight` method was changed in a way that didn't account for unauthenticated users. Update the method to handle this scenario and add a test. The dashboard view is updated to set null accounts more consistently with the change list view. Change-Id: Id33808505ffb6c3f722a963d8e27dd8dba112dec

diff --git a/polygerrit-ui/app/elements/change-list/gr-change-list/gr-change-list.js b/polygerrit-ui/app/elements/change-list/gr-change-list/gr-change-list.js
index c098ef6..3489db0 100644
--- a/polygerrit-ui/app/elements/change-list/gr-change-list/gr-change-list.js
+++ b/polygerrit-ui/app/elements/change-list/gr-change-list/gr-change-list.js

@@ -44,7 +44,7 @@
        */
       account: {
         type: Object,
-        value() { return {}; },
+        value: null,
       },
       /**
        * An array of ChangeInfo objects to render.
@@ -227,12 +227,13 @@
     _computeItemNeedsReview(account, change, showReviewedState) {
       return showReviewedState && !change.reviewed &&
           this.changeIsOpen(change.status) &&
-          account._account_id != change.owner._account_id;
+          (!account || account._account_id != change.owner._account_id);
     },
 
     _computeItemHighlight(account, change) {
       // Do not show the assignee highlight if the change is not open.
       if (!change.assignee ||
+          !account ||
           CLOSED_STATUS.indexOf(change.status) !== -1) {
         return false;
       }

diff --git a/polygerrit-ui/app/elements/change-list/gr-change-list/gr-change-list_test.html b/polygerrit-ui/app/elements/change-list/gr-change-list/gr-change-list_test.html
index 8c37d25..aed48e3 100644
--- a/polygerrit-ui/app/elements/change-list/gr-change-list/gr-change-list_test.html
+++ b/polygerrit-ui/app/elements/change-list/gr-change-list/gr-change-list_test.html

@@ -481,6 +481,11 @@
       assert.isFalse(items[1].hasAttribute('highlight'));
     });
 
+    test('_computeItemHighlight gives false for null account', () => {
+      assert.isFalse(
+          element._computeItemHighlight(null, {assignee: {_account_id: 42}}));
+    });
+
     test('_computeItemAbsoluteIndex', () => {
       sandbox.stub(element, '_computeLabelNames');
       element.sections = [

diff --git a/polygerrit-ui/app/elements/change-list/gr-dashboard-view/gr-dashboard-view.js b/polygerrit-ui/app/elements/change-list/gr-dashboard-view/gr-dashboard-view.js
index 7c04c1f..cce291b 100644
--- a/polygerrit-ui/app/elements/change-list/gr-dashboard-view/gr-dashboard-view.js
+++ b/polygerrit-ui/app/elements/change-list/gr-dashboard-view/gr-dashboard-view.js

@@ -72,7 +72,7 @@
     properties: {
       account: {
         type: Object,
-        value() { return {}; },
+        value: null,
       },
       /** @type {{ selectedChangeIndex: number }} */
       viewState: Object,