PolyGerrit: Add assignee to the dashboard

GWTUI does this.

Bug: Issue 5266
Change-Id: Ie57f1ee05275afefce982d1c01dc3acedbd9b002
diff --git a/polygerrit-ui/app/behaviors/gr-change-table-behavior/gr-change-table-behavior.html b/polygerrit-ui/app/behaviors/gr-change-table-behavior/gr-change-table-behavior.html
index 7037b53..20568e6 100644
--- a/polygerrit-ui/app/behaviors/gr-change-table-behavior/gr-change-table-behavior.html
+++ b/polygerrit-ui/app/behaviors/gr-change-table-behavior/gr-change-table-behavior.html
@@ -28,6 +28,7 @@
           'Subject',
           'Status',
           'Owner',
+          'Assignee',
           'Project',
           'Branch',
           'Updated',
diff --git a/polygerrit-ui/app/behaviors/gr-change-table-behavior/gr-change-table-behavior_test.html b/polygerrit-ui/app/behaviors/gr-change-table-behavior/gr-change-table-behavior_test.html
index 19837cc..c265db87c 100644
--- a/polygerrit-ui/app/behaviors/gr-change-table-behavior/gr-change-table-behavior_test.html
+++ b/polygerrit-ui/app/behaviors/gr-change-table-behavior/gr-change-table-behavior_test.html
@@ -61,6 +61,7 @@
         'Subject',
         'Status',
         'Owner',
+        'Assignee',
         'Project',
         'Branch',
         'Updated',
@@ -71,6 +72,7 @@
       columns = [
         'Subject',
         'Status',
+        'Assignee',
         'Project',
         'Branch',
         'Size',
@@ -85,6 +87,7 @@
         'Subject',
         'Status',
         'Owner',
+        'Assignee',
         'Project',
         'Branch',
         'Updated',
@@ -96,6 +99,7 @@
         'Subject',
         'Status',
         'Owner',
+        'Assignee',
         'Branch',
         'Updated',
         'Size',
diff --git a/polygerrit-ui/app/elements/change-list/gr-change-list-item/gr-change-list-item.html b/polygerrit-ui/app/elements/change-list/gr-change-list-item/gr-change-list-item.html
index e1b88e8..83a4362 100644
--- a/polygerrit-ui/app/elements/change-list/gr-change-list-item/gr-change-list-item.html
+++ b/polygerrit-ui/app/elements/change-list/gr-change-list-item/gr-change-list-item.html
@@ -137,6 +137,10 @@
         hidden$="[[isColumnHidden('Owner', visibleChangeTableColumns)]]">
       <gr-account-link account="[[change.owner]]"></gr-account-link>
     </td>
+    <td class="cell assignee"
+        hidden$="[[isColumnHidden('Assignee', visibleChangeTableColumns)]]">
+      <gr-account-link account="[[change.assignee]]"></gr-account-link>
+    </td>
     <td class="cell project"
         hidden$="[[isColumnHidden('Project', visibleChangeTableColumns)]]">
       <a href$="[[_computeProjectURL(change.project)]]">[[change.project]]</a>
diff --git a/polygerrit-ui/app/elements/change-list/gr-change-list-item/gr-change-list-item_test.html b/polygerrit-ui/app/elements/change-list/gr-change-list-item/gr-change-list-item_test.html
index 8b13aa7..cd07b5a 100644
--- a/polygerrit-ui/app/elements/change-list/gr-change-list-item/gr-change-list-item_test.html
+++ b/polygerrit-ui/app/elements/change-list/gr-change-list-item/gr-change-list-item_test.html
@@ -119,6 +119,7 @@
         'Subject',
         'Status',
         'Owner',
+        'Assignee',
         'Project',
         'Branch',
         'Updated',
@@ -138,6 +139,7 @@
         'Subject',
         'Status',
         'Owner',
+        'Assignee',
         'Project',
         'Branch',
         'Updated',
@@ -157,6 +159,7 @@
         'Subject',
         'Status',
         'Owner',
+        'Assignee',
         'Branch',
         'Updated',
         'Size',
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 704606c..1994bb9 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
@@ -311,6 +311,7 @@
             'Subject',
             'Status',
             'Owner',
+            'Assignee',
             'Project',
             'Branch',
             'Updated',
@@ -341,6 +342,7 @@
             'Subject',
             'Status',
             'Owner',
+            'Assignee',
             'Branch',
             'Updated',
             'Size',
diff --git a/polygerrit-ui/app/elements/settings/gr-change-table-editor/gr-change-table-editor_test.html b/polygerrit-ui/app/elements/settings/gr-change-table-editor/gr-change-table-editor_test.html
index 00ef16f..e1753ba 100644
--- a/polygerrit-ui/app/elements/settings/gr-change-table-editor/gr-change-table-editor_test.html
+++ b/polygerrit-ui/app/elements/settings/gr-change-table-editor/gr-change-table-editor_test.html
@@ -45,6 +45,7 @@
         'Subject',
         'Status',
         'Owner',
+        'Assignee',
         'Project',
         'Branch',
         'Updated',
@@ -87,6 +88,7 @@
       element.set('displayedColumns', [
         'Status',
         'Owner',
+        'Assignee',
         'Project',
         'Branch',
         'Updated',
@@ -147,6 +149,7 @@
           [
             'Status',
             'Owner',
+            'Assignee',
             'Project',
             'Branch',
             'Updated',
@@ -158,6 +161,7 @@
             'Subject',
             'Status',
             'Owner',
+            'Assignee',
             'Project',
             'Branch',
             'Updated',