Add common test configs for properties that take lengths

third_party/WebKit/LayoutTests/typedcssom/inlinestyle/properties/border-bottom-style.html

Index: third_party/WebKit/LayoutTests/typedcssom/inlinestyle/properties/border-bottom-style.html
diff --git a/third_party/WebKit/LayoutTests/typedcssom/inlinestyle/properties/border-bottom-style.html b/third_party/WebKit/LayoutTests/typedcssom/inlinestyle/properties/border-bottom-style.html
index 6564e7fd3224eb366f2c6e17c1b6cb771fff31ac..1f5d77cbd6d55ab0d14e9ef75b44ca09d46c500a 100644
--- a/third_party/WebKit/LayoutTests/typedcssom/inlinestyle/properties/border-bottom-style.html
+++ b/third_party/WebKit/LayoutTests/typedcssom/inlinestyle/properties/border-bottom-style.html
@@ -3,9 +3,8 @@
 <script src='../../../resources/testharnessreport.js'></script>
 <script src='property-suite.js'></script>
 <script src='config-templates.js'></script>
-
 <script>
-  let config = Object.assign({}, config_templates.borderConfig);
-  config['property'] = 'border-bottom-style';
-  runInlineStylePropertyMapTests(config);
-</script>
+let config = config_templates.borderConfig();
+config['property'] = 'border-bottom-style';
+runInlineStylePropertyMapTests(config);
+</script>