SelectionAutoscroll should not happen in user-select:none.

third_party/WebKit/LayoutTests/fast/events/autoscroll-disabled-user-select-none.html

+<script src="../../resources/testharness.js"></script>
+<script src="../../resources/testharnessreport.js"></script>
+<div id="container" style="height: 400px; overflow: auto;">
+  <div style="-webkit-user-select:none; height: 2000px; background-color: yellow">
+    Hello World! Hello Woorld! Hello Wooorld! Hello Woooorld!<br />
+    Hello World! Hello Woorld! Hello Wooorld! Hello Woooorld!<br />
+    Hello World! Hello Woorld! Hello Wooorld! Hello Woooorld!<br />
+    Hello World! Hello Woorld! Hello Wooorld! Hello Woooorld!<br />
+    Hello World! Hello Woorld! Hello Wooorld! Hello Woooorld!<br />
+  </div>
+</div>
+<script>
+var testSelectNone = async_test("Selection-autoscroll should not be triggered when the selection happens in an element with user-select:none");
+testSelectNone.step(function() {
+    if (!window.eventSender)
+        return;
+    var dragStartX = 50;
+    var dragStartY = 50;
+    var dragEndX = 60;
+    var dragEndY = 400;
+    var container = document.getElementById("container");
+
+    eventSender.dragMode = false;
+    eventSender.mouseMoveTo(dragStartX, dragStartY);
+    eventSender.mouseDown();
+    eventSender.mouseMoveTo(dragEndX, dragEndY);
+
+    requestAnimationFrame(function() {
+        assert_equals(container.scrollTop, 0);
+        testSelectNone.done();
+    });
+});
+</script>