From 65a5b48c38be5866a9e9d2e450218ed7f739aadc Mon Sep 17 00:00:00 2001
From: Kevin Schaaf <kschaaf@google.com>
Date: Wed, 10 Apr 2019 14:47:39 -0700
Subject: [PATCH] Avoid upgrading template if no hostProps, for better perf.

---
 lib/utils/templatize.js | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/lib/utils/templatize.js b/lib/utils/templatize.js
index 9f05135470..7cdcb8ca4a 100644
--- a/lib/utils/templatize.js
+++ b/lib/utils/templatize.js
@@ -364,7 +364,11 @@ function createTemplatizerClass(template, templateInfo, options) {
  */
 function addPropagateEffects(template, templateInfo, options) {
   let userForwardHostProp = options.forwardHostProp;
-  if (userForwardHostProp) {
+  const hasHostProps = templateInfo.hasHostProps ||
+    (templateInfo.hasHostProps = 
+      Boolean(templateInfo.hostProps && 
+        Object.keys(templateInfo.hostProps).length));
+  if (userForwardHostProp && hasHostProps) {
     // Provide data API and property effects on memoized template class
     let klass = templateInfo.templatizeTemplateClass;
     if (!klass) {