Add detection for support of scrollToOptions mode of window.scrollTo() (#2575)

feature-detects/scrolltooptions.js

@@ -0,0 +1,34 @@
+/*!
+{
+  "name": "scrollToOptions dictionary",
+  "property": "scrolltooptions",
+  "caniuse": "mdn-api_scrolltooptions",
+  "notes": [{
+    "name": "MDN docs",
+    "href": "https://developer.mozilla.org/en-US/docs/Web/API/Window/scrollTo"
+  }],
+  "authors": ["Oliver Tušla (@asmarcz)", "Chris Smith (@chris13524)"]
+}
+!*/
+define(['Modernizr', 'createElement', 'getBody'], function (Modernizr, createElement, getBody) {
+  Modernizr.addTest('scrolltooptions', function () {
+    var body = getBody();
+    var returnTo = window.pageYOffset;
+    var needsFill = body.clientHeight <= window.innerHeight;
+    if (needsFill) {
+      var div = createElement('div');
+      div.style.height = (window.innerHeight - body.clientHeight + 1) + 'px';
+      div.style.display = 'block';
+      body.appendChild(div);
+    }
+    window.scrollTo({
+      top: 1
+    });
+    var result = window.pageYOffset !== 0;
+    if (needsFill) {
+      body.removeChild(div);
+    }
+    window.scrollTo(0, returnTo);
+    return result;
+  });
+});

lib/config-all.json

@@ -268,6 +268,7 @@
     "requestanimationframe",
     "script/async",
     "script/defer",
+    "scrolltooptions",
     "serviceworker",
     "speech/speech-recognition",
     "speech/speech-synthesis",