From e7d37afaab7f02344ae9c2c518d124d68ab0af46 Mon Sep 17 00:00:00 2001
From: Alejandro Such <alejandro.such@gmail.com>
Date: Thu, 1 Jun 2017 17:31:33 +0200
Subject: [PATCH] Add passive event listener if available, to make the page
 more responsive.

---
 src/jqLite.js | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/src/jqLite.js b/src/jqLite.js
index ad59fbd1af2b..e1343cabbe66 100644
--- a/src/jqLite.js
+++ b/src/jqLite.js
@@ -851,6 +851,21 @@ function specialMouseHandlerWrapper(target, event, handler) {
 // These functions chain results into a single
 // selector.
 //////////////////////////////////////////
+function passiveOptionSupported() {
+  var supportsPassiveOption = false;
+  try {
+    var opts = Object.defineProperty({}, 'passive', {
+      get: function() {
+        supportsPassiveOption = true;
+      }
+    });
+    window.addEventListener('test', null, opts);
+    // eslint-disable-next-line no-empty
+  } catch (e) {
+  }
+  return supportsPassiveOption;
+}
+
 forEach({
   removeData: jqLiteRemoveData,
 
@@ -881,7 +896,7 @@ forEach({
         eventFns = events[type] = [];
         eventFns.specialHandlerWrapper = specialHandlerWrapper;
         if (type !== '$destroy' && !noEventListener) {
-          element.addEventListener(type, handle);
+          element.addEventListener(type, handle, passiveOptionSupported() ? { passive: true } : false);
         }
       }