DevTools: Move checkbox title element into Shadow DOM

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

 /*
  * Copyright (c) 2014 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 {
     padding: 0;
     margin: 0;
     display: inline-flex;
@@ skipping 41 matching lines @@
     -webkit-mask-position: -128px -110px;
 }
 
 @media (-webkit-min-device-pixel-ratio: 1.1) {
 input.dt-checkbox-themed:after {
     -webkit-mask-image: url(Images/toolbarButtonGlyphs_2x.png);
 }
 
 } /* media */
 
-::content .dt-checkbox-text {
+.dt-checkbox-text {
     margin-left: 3px;
+    overflow: hidden;
+    text-overflow: ellipsis;
 }
 
-::content .dt-checkbox-subtitle {
+.dt-checkbox-subtitle {
     color: gray;
 }