DevTools: Fix timeline overview flickering

third_party/WebKit/Source/devtools/front_end/ui/glassPane.css

 /*
  * Copyright 2017 The Chromium Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 :host {
     position: absolute !important;
     top: 0;
     bottom: 0;
@@ skipping 12 matching lines @@
     pointer-events: none;
 }
 
 .widget {
     display: flex;
     background-color: transparent;
     pointer-events: auto;
     flex: none;
 }
 
+.no-pointer-events {
+    pointer-events: none;
+}
+
 .arrow-top {
     margin-top: -19px;
     margin-left: -9px;
 }
 
 .arrow-bottom {
     margin-left: -9px;
 }
 
 .arrow-left {
     margin-left: -19px;
     margin-top: -9px;
 }
 
 .arrow-right {
     margin-top: -9px;
 }
 
 .arrow-none {
     display: none;
 }
 
 :host-context(.-theme-with-dark-background) .arrow {
     -webkit-filter: invert(80%);
 }