From 8c1a5765b88f15926e3ad6c555904c834e36547a Mon Sep 17 00:00:00 2001
From: Daniel Freedman <dfreedm@google.com>
Date: Mon, 20 Mar 2017 16:02:27 -0700
Subject: [PATCH] Remove useless id check on mixins

Fixes #4445
---
 lib/utils/mixin.html | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/lib/utils/mixin.html b/lib/utils/mixin.html
index 91dbdbfec7..85a04b0e3a 100644
--- a/lib/utils/mixin.html
+++ b/lib/utils/mixin.html
@@ -51,9 +51,7 @@
   Polymer.dedupingMixin = function(mixin) {
     mixin = cachingMixin(mixin);
     // maintain a unique id for each mixin
-    if (!mixin.__id) {
-      mixin.__dedupeId = ++dedupeId;
-    }
+    mixin.__dedupeId = ++dedupeId;
     return function(base) {
       let baseSet = base.__mixinSet;
       if (baseSet && baseSet[mixin.__dedupeId]) {