utility.js: replace Utility.scroll_to with Element.scrollIntoView.

https://developer.mozilla.org/en-US/docs/Web/API/Element/scrollIntoView
https://caniuse.com/#feat=scrollintoview

app/javascript/src/javascripts/comments.js

@@ -39,7 +39,7 @@ Comment.show_new_comment_form = function(e) {
   $(e.target).hide();
   var $form = $(e.target).closest("div.new-comment").find("form");
   $form.show();
-  Utility.scroll_to($form);
+  $form[0].scrollIntoView(false);
   e.preventDefault();
 }
 

app/javascript/src/javascripts/notes.js

@@ -145,7 +145,7 @@ let Note = {
       Note.Body.show(note_id);
       $(".note-box-highlighted").removeClass("note-box-highlighted");
       $note_box.addClass("note-box-highlighted");
-      Utility.scroll_to($note_box);
+      $note_box[0].scrollIntoView(false);
     },
 
     resize_inner_border: function($note_box) {

app/javascript/src/javascripts/utility.js

@@ -12,24 +12,6 @@ Utility.test_max_width = function(width) {
   return mq.matches;
 }
 
-Utility.scrolling = false;
-
-Utility.scroll_to = function(element) {
-  if (Utility.scrolling) {
-    return;
-  } else {
-    Utility.scrolling = true;
-  }
-
-  var top = null;
-  if (typeof element === "number") {
-    top = element;
-  } else {
-    top = element.offset().top - 10;
-  }
-  $('html, body').animate({scrollTop: top}, 300, "linear", function() {Utility.scrolling = false;});
-}
-
 Utility.notice_timeout_id = undefined;
 
 Utility.notice = function(msg, permanent) {