Add "Start review" workflow using work_in_progress

Feature: Issue 3799
Feature: Issue 5310
Change-Id: I262c156b0155d1b64b84a9df91279979b41daede

polygerrit-ui/app/elements/change/gr-reply-dialog/gr-reply-dialog_test.html

@@ -676,5 +676,23 @@ limitations under the License.
 
       assert.isTrue(cancelHandler.called);
     });
+
+    test('_computeMessagePlaceholder', function() {
+      assert.equal(
+          element._computeMessagePlaceholder(false),
+          'Say something nice...');
+      assert.equal(
+          element._computeMessagePlaceholder(true),
+          'Add a note for your reviewers...');
+    });
+
+    test('_computeSendButtonLabel', function() {
+      assert.equal(
+          element._computeSendButtonLabel(false),
+          'Send');
+      assert.equal(
+          element._computeSendButtonLabel(true),
+          'Start review');
+    });
   });
 </script>