Migrate root scroller test away from using EventSender

Bug: 1047176
Change-Id: I958edb07c881aa604ecb474f4aa735b69002c445
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2163649Reviewed-by: David Bokan <bokan@chromium.org>
Commit-Queue: Navid Zolghadr <nzolghadr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#762155}

third_party/blink/web_tests/rootscroller/scroll-non-descendant-of-root-scroller.html

@@ -61,6 +61,7 @@
 
 <script src="../resources/testharness.js"></script>
 <script src="../resources/testharnessreport.js"></script>
+<script src='../resources/gesture-util.js'></script>
 
 <script>
   var rootScroller = document.querySelector('#rootscroller');
@@ -73,9 +74,7 @@
   var x = dialogRect.left + dialogRect.width / 2;
   var y = dialogRect.top + dialogRect.height / 2;
 
-  test(function() {
-      if (!window.eventSender)
-          return;
+  promise_test(async () => {
 
       // Sanity check - there should be no initial scroll.
       assert_equals(dialog.scrollLeft, 0);
@@ -84,10 +83,9 @@
       assert_equals(rootscroller.scrollTop, 0);
 
       // This scroll should fully scroll the dialog
-          eventSender.gestureScrollBegin(x, y);
-          eventSender.gestureScrollUpdate(-3000, 0);
-          eventSender.gestureScrollUpdate(0, -3000);
-          eventSender.gestureScrollEnd(0, 0);
+      await smoothScrollWithXY(3000, 3000, x, y, GestureSourceType.TOUCH_INPUT, SPEED_INSTANT);
+
+      await waitFor( () => { return dialog.scrollLeft == dialog.scrollWidth - dialog.clientWidth; } );
 
       assert_equals(dialog.scrollLeft, dialog.scrollWidth - dialog.clientWidth);
       assert_equals(dialog.scrollTop, dialog.scrollHeight - dialog.clientHeight);
@@ -97,10 +95,9 @@
       // This scroll would normally chain up to the viewport but the "real"
       // viewport has no scrolling. Make sure we don't scroll the
       // document.rootScroller.
-          eventSender.gestureScrollBegin(x, y);
-          eventSender.gestureScrollUpdate(-3000, 0);
-          eventSender.gestureScrollUpdate(0, -3000);
-          eventSender.gestureScrollEnd(0, 0);
+      await smoothScrollWithXY(3000, 3000, x, y, GestureSourceType.TOUCH_INPUT, SPEED_INSTANT);
+
+      await waitFor( () => { return dialog.scrollLeft == dialog.scrollWidth - dialog.clientWidth; } );
 
       assert_equals(dialog.scrollLeft, dialog.scrollWidth - dialog.clientWidth);
       assert_equals(dialog.scrollTop, dialog.scrollHeight - dialog.clientHeight);