DevTools: Migrate from -webkit-user-modify to contenteditable

third_party/WebKit/Source/devtools/front_end/elements/elementsPanel.css

 /*
  * Copyright (C) 2006, 2007, 2008 Apple Inc.  All rights reserved.
  * Copyright (C) 2009 Anthony Ricaud <rik@webkit.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
@@ skipping 312 matching lines @@
 }
 
 .styles-element-classes-pane .new-class-input {
     padding-left: 3px;
     padding-right: 3px;
     overflow: hidden;
     border: 1px solid #ddd;
     line-height: 15px;
     margin-left: 3px;
     width: calc(100% - 7px);
-    -webkit-user-modify: read-write-plaintext-only;
     background-color: #fff;
     cursor: text;
 }
 
 .styles-element-state-pane > div {
     margin: 8px 4px 6px;
 }
 
 .styles-element-state-pane > table {
     width: 100%;
@@ skipping 188 matching lines @@
     display: flex;
     flex-direction: row;
     align-items: center;
 }
 
 .elements-tree-header-frame {
     margin-left: 6px;
     margin-right: 6px;
     flex: none;
 }